@creejs/commons-events/dist/umd/index.dev.js

Commons EventEmitter

(function (global, factory) {
  typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
  typeof define === 'function' && define.amd ? define(['exports'], factory) :
  (global = typeof globalThis !== 'undefined' ? globalThis : global || self, factory(global.CommonsLang = {}));
})(this, (function (exports) { 'use strict';

  var u={isFunction:c,isNil:y};function c(t){return "function"==typeof t}function y(t){return null==t}function m(t){return null!=t&&"number"==typeof t}function N(t){return null!=t&&"string"==typeof t}function $(t){return null!=t&&"symbol"==typeof t}var C={assertNumber:q,assertFunction:W,assertNotNil:V,assertString:M,assertStringOrSymbol:function(t,r){if(!N(t)&&!$(t))throw new Error(`${r?'"'+r+'" ':""}Not String or Symbol: type=${typeof t} value=${Z(t)}`)}};function M(t,r){if(!N(t))throw new Error(`${r?'"'+r+'" ':""}Not String: type=${typeof t} value=${Z(t)}`)}function q(t,r){if(!m(t))throw new Error(`${r?'"'+r+'" ':""}Not Number: type=${typeof t} value=${Z(t)}`)}function W(t,r){if(!c(t))throw new Error(`${r?'"'+r+'" ':""}Not Function: type=${typeof t} value=${Z(t)}`)}function V(t,r){if(y(t))throw new Error((r?'"'+r+'" ':"")+"Should Not Nil")}function Z(t){if(null===t)return "null";if(void 0===t)return "undefined";let r;try{r=JSON.stringify(t);}catch(e){r=t.toString();}return r}new TextDecoder;new TextEncoder;

  const DefaultOwner = 'DOwner$#$';

  // 3rd
  // internal

  // module vars
  const { assertFunction: assertFunction$2, assertNotNil: assertNotNil$1 } = C;
  /**
   * Wraps a function to be called when an event is fired.
   * @typedef {import('./event.js').default} Event
   * @class Listener
   */
  class Listener {
    /**
     * @param {Event} event
     * @param {function} callback - The function to be called when event is fired
     * @param {boolean} [isOnce=false] - is a one time listener?
     */
    constructor (event, callback, isOnce = false) {
      assertNotNil$1(event, 'event');
      assertFunction$2(callback, 'callback');
      this._event = event;
      this._callback = callback;
      this._isOnce = !!isOnce; // is Once Listener?
      this._owner = undefined;
    }

    /**
     * Sets the owner of this listener.
     * @param {*} owner - The owner object to be associated with this listener.
     */
    set owner (owner) {
      this._owner = owner;
    }

    get owner () {
      return this._owner === DefaultOwner ? undefined : this._owner
    }

    get event () {
      return this._event
    }

    get isOnce () {
      return this._isOnce
    }

    /**
     * Checks if the provided function is the same as the listener's wrapped function.
     * @param {Function} callback - The function to compare against.
     * @returns {boolean} True if the functions are the same, false otherwise.
     */
    isSameCallback (callback) {
      return this._callback === callback
    }

    get callback () {
      return this._callback
    }

    /**
     * Invokes the stored function with the provided arguments.
     * @param {...*} args - Arguments to pass to the function.
     * @returns {*} The result of the function invocation.
     */
    invoke (...args) {
      try {
        return this._callback(...args)
      } finally {
        if (this._isOnce) {
          try {
            this._event._remove(this);
          } catch (err) {
            // do nothing
            console.warn(err);
          }
        }
      }
    }

    /**
     * Invokes the listener with the provided arguments.
     * Alias for {@linkcode Listener.invoke}
     * @param {...*} args - Arguments to be passed to the listener.
     * @returns {*} The result of the listener invocation.
     */
    listener (...args) {
      return this.invoke(...args)
    }
  }

  // 3rd
  // internal

  // module vars
  const { isFunction, isNil: isNil$1 } = u;
  const { assertStringOrSymbol: assertStringOrSymbol$1, assertFunction: assertFunction$1 } = C;

  /**
   * An Event definition
   * 1. listeners are grouped by owner
   *    * if not specified, group it into one Default owner
   * 2. one listener may belong to multiple owners
   * 3. one owner may have multiple listeners
   */
  class Event {
    static get DefaultOwner () {
      return DefaultOwner
    }

    /**
     * Creates a new Event instance with the specified name.
     * @param {string|Symbol} eventName - The name of the event.
     */
    constructor (eventName) {
      assertStringOrSymbol$1(eventName, 'eventName');
      this._name = eventName;
      /**
       * use Set to store unique listeners
       * @type {Set<function>}
       */
      this._callbacks = new Set();
      /**
       * @type {Array<Listener>}
       */
      this._listeners = []; // user array to keep order
      /**
       * @type {Map<function, Set<Listener>>}
       */
      this._callback2Listeners = new Map();
      /**
       * use listener to index owners. One Listener Instance only belongs to one owner
       * @type {Map<Listener, *>}
      */
      this._listener2Owner = new Map();
      /**
       * use "owner" to group listeners; one owner may have multiple listeners
       * @type {Map<*, Set<Listener>>}
       */
      this._owner2Listeners = new Map();
    }

    /**
     * Name of the event.
     * @returns {string|Symbol}
     */
    get name () {
      return this._name
    }

    isEmpty () {
      return this._callbacks.size === 0
    }

    /**
     * Returns a copy of the raw listeners array.
     * @returns {Array<Listener>} A shallow copy of the listeners array.
     */
    rawListeners () {
      return [...this._listeners]
    }

    /**
     * Returns the number of listeners listening for the event.
     * If callback is provided, it will return how many times the callback is found in the list of the listeners
     * @param {Function} [callback] - The callback function to count
     * @returns {number}
     */
    listenerCount (callback) {
      if (callback == null) {
        return this._listeners.length
      }
      return this._callback2Listeners.get(callback)?.size ?? 0
    }

    /**
     * Returns a shallow copy of the registered callbacks array.
     * if one callback function is added multiple times, it will be returned multiple times.
     * @returns {Array<function>} A new array containing all registered callbacks.
     */
    callbacks () {
      return [...this.rawListeners().map(listener => listener.callback)]
    }

    /**
     * Emits current event, invoking all registered listeners by order.
     * @param {...*} args - Arguments to be passed to each listener.
     * @returns {boolean} True if the event had listeners, false otherwise.
     */
    emit (...args) {
      if (this._listeners.length === 0) {
        return false
      }
      // Clone _listeners, it may be changed during call listener
      for (const listener of [...this._listeners]) {
        listener.invoke(...args);
      }
      return true
    }

    /**
     * Emits current event, invoking all registered listeners by order.
     * @param {string|Symbol} owner
     * @param {...*} args - Arguments to be passed to each listener.
     * @returns {boolean} True if the event had listeners, false otherwise.
     */
    emitOwner (owner, ...args) {
      if (this._listeners.length === 0) {
        return false
      }
      const listeners = this._owner2Listeners.get(owner);
      if (listeners == null) {
        return false
      }
      // Clone _listeners, it may be changed during call listener
      for (const listener of [...listeners]) {
        listener.invoke(...args);
      }
      return true
    }

    /**
     * Checks if listener is registered with this event.
     * @param {function} callback - The listener function to check.
     * @returns {boolean} True if the listener is registered, false otherwise.
     */
    hasListener (callback) {
      if (!isFunction(callback)) {
        return false
      }
      return this._callbacks.has(callback)
    }

    /**
     * Checks if owner has any registered listeners.
     * @param {*} owner - The owner to check for registered listeners.
     * @returns {boolean} True if the owner has listeners, false otherwise.
     */
    hasOwner (owner) {
      if (isNil$1(owner)) {
        return false
      }
      return this._owner2Listeners.has(owner)
    }

    /**
     * Adds an event listener
     * @param {function} callback - The callback function to be invoked when the event occurs.
     * @param {*} [owner] - use "owner" to group listeners, then can remove all listeners for an owner.
     * @returns {boolean} true if added, false otherwise.
     */
    addListener (callback, owner) {
      return this._addListener(callback, owner, false, false)
    }

    /**
     * Prepends a listener callback to the beginning of the listeners array.
     * No checks are made to see if the listener has already been added.
     * Multiple calls passing the same combination of eventName and listener will result in the listener being added,
     * and called, multiple times.
     * @param {Function} callback - The callback function to be executed when the event is emitted.
     * @param {Object} owner - The owner object to which the listener belongs.
     * @returns {boolean}
     */
    prependListener (callback, owner) {
      return this._addListener(callback, owner, false, true)
    }

    /**
     * Adds a one-time listener for the event. The listener is automatically removed after being invoked once.
     * @param {Function} callback - The function to call when the event is triggered.
     * @param {Object} [owner] - The object that owns the callback (used for binding `this` context).
     * @returns {boolean}
     */
    addOnceListener (callback, owner) {
      return this._addListener(callback, owner, true, false)
    }

    /**
     * Adds a one-time event listener that will be automatically removed after being triggered once.
     * The listener will only be triggered if the event is pretended (simulated).
     * @param {Function} callback - The function to call when the event is triggered.
     * @param {Object} owner - The object that owns the listener (used for reference tracking).
     * @returns {boolean} The listener function that was added.
     */
    prependOnceListener (callback, owner) {
      return this._addListener(callback, owner, true, true)
    }

    /**
     * Adds a listener for the event.
     * @param {Function} callback - The callback function to be executed when the event occurs
     * @param {*} [owner] - The owner object that the listener belongs to (defaults to DeaultOwner)
     * @param {boolean} [isOnce=false] - Whether the listener should be removed after first invocation
     * @param {boolean} [isPrepend=false] - Whether the listener should be inert at the beginning of the listeners array
     * @returns {boolean} Returns true if listener was added successfully, false if callback is nil or duplicate
     * @protected
     */
    _addListener (callback, owner, isOnce, isPrepend) {
      if (isNil$1(callback)) {
        return false
      }
      assertFunction$1(callback);
      if (!this._callbacks.has(callback)) {
        this._callbacks.add(callback);
      }
      // a listener must belong to an owner
      owner = owner ?? DefaultOwner;

      // use Listener to wrap callback
      const listener = new Listener(this, callback, isOnce);
      listener.owner = owner;
      if (isPrepend) {
        this._listeners.unshift(listener);
      } else {
        this._listeners.push(listener);
      }

      // index, rapadly find one listener's owner
      this._listener2Owner.set(listener, owner);

      // one callback function may be registered many times
      let callbackListeners = this._callback2Listeners.get(callback);
      if (callbackListeners == null) {
        callbackListeners = new Set();
        this._callback2Listeners.set(callback, callbackListeners);
      }
      callbackListeners.add(listener);

      // group by owner
      let ownerListeners = this._owner2Listeners.get(owner);
      if (ownerListeners == null) {
        ownerListeners = new Set();
        this._owner2Listeners.set(owner, ownerListeners);
      }
      ownerListeners.add(listener);

      return true
    }

    /**
     * Removes a callback
     * @param {Function} callback - The callback function to remove.
     * @returns {boolean} true if removed, false otherwise.
     */
    removeListener (callback) {
      if (isNil$1(callback)) {
        return false
      }
      if (!this._callbacks.has(callback)) {
        return false
      }
      this._callbacks.delete(callback);

      const listeners = this._callback2Listeners.get(callback);
      if (listeners == null) { // should not happen
        return false
      }
      this._callback2Listeners.delete(callback);
      for (const listener of listeners) {
        // remove from global index
        const index = this._listeners.indexOf(listener);
        index !== -1 && this._listeners.splice(this._listeners.indexOf(listener), 1);

        // remove from owner index
        const owner = this._listener2Owner.get(listener);
        if (owner == null) {
          continue
        }
        this._listener2Owner.delete(listener);
        const ownerListeners = this._owner2Listeners.get(owner);
        if (ownerListeners == null) {
          continue
        }
        ownerListeners.delete(listener);
        if (ownerListeners.size === 0) {
          this._owner2Listeners.delete(owner);
        }
      }
      return true
    }

    /**
     * Removes a listener from both global and owner indexes.
     * @param {Listener} listener - The listener function to remove
     */
    _remove (listener) {
      // remove from global index
      const index = this._listeners.indexOf(listener);
      index !== -1 && this._listeners.splice(index, 1);

      // clean callback index
      const { callback } = listener;
      const callbackListeners = this._callback2Listeners.get(callback);
      if (callbackListeners != null) {
        callbackListeners.delete(listener);
        if (callbackListeners.size === 0) {
          this._callback2Listeners.delete(callback);
          this._callbacks.delete(callback);
        }
      }

      // remove from owner index
      const owner = this._listener2Owner.get(listener);
      if (owner == null) {
        return
      }
      this._listener2Owner.delete(listener);
      const ownerListeners = this._owner2Listeners.get(owner);
      if (ownerListeners == null) {
        return
      }
      ownerListeners.delete(listener);
      if (ownerListeners.size === 0) {
        this._owner2Listeners.delete(owner);
      }
    }

    /**
     * Removes all event listeners
     * @param {*} [owner] - Without owner, all listeners will be removed; otherwise, only listeners of "owner" will be removed.
     * @returns {this}
     */
    removeAllListeners (owner) {
      // remove listeners of owner
      if (isNil$1(owner)) {
        // remove all Listeners
        this._callbacks.clear();
        this._listeners.length = 0;
        this._callback2Listeners.clear();
        this._listener2Owner.clear();
        this._owner2Listeners.clear();
        return this
      }
      // all listeners of the owner
      const ownerListeners = this._owner2Listeners.get(owner);
      // no owner
      if (ownerListeners == null) {
        return this
      }
      // clear owner index
      this._owner2Listeners.delete(owner);
      // clearn listeners of owner one by one
      for (const listener of ownerListeners) {
        // remove from global index
        const index = this._listeners.indexOf(listener);
        index !== -1 && this._listeners.splice(this._listeners.indexOf(listener), 1);

        // clean listener-owner index
        this._listener2Owner.delete(listener);

        // one callback function may be registered many times, has many Listeners
        const { callback } = listener;
        const callbackListeners = this._callback2Listeners.get(callback);
        if (callbackListeners == null) {
          continue
        }
        callbackListeners.delete(listener);
        if (callbackListeners.size === 0) {
          this._callback2Listeners.delete(callback);
          this._callbacks.delete(callback);
        }
      }
      return this
    }
  }

  // 3rd
  // internal

  /**
   * @typedef {{
   *  on(eventName:string, listener:function, owner?:any): EventEmitterLike,
   *  addListener(eventName:string, listener:function, owner?:any): EventEmitterLike,
   *  off(eventName:string, listener:function): EventEmitterLike,
   *  removeListener(eventName:string, listener:function): EventEmitterLike,
   *  offAll(eventName:string, owner:any): EventEmitterLike,
   *  offOwner(owner:any): EventEmitterLike,
   *  removeAllListeners(eventName:string): EventEmitterLike,
   *  once(eventName:string, listener:function, owner?:any): EventEmitterLike,
   *  emit(eventName:string, ...args:any[]): EventEmitterLike,
   *  emitOwner(eventName:string, owner:any, ...args:any[]): EventEmitterLike,
   * }} EventEmitterLike
   */

  // module vars
  const { isNil } = u;
  const {
    assertString, assertFunction, assertNumber,
    assertStringOrSymbol, assertNotNil
  } = C;

  /**
   * methods allowed to mixin other objects
   */
  const MixinMethods = [
    'on', 'once', 'addListener', 'prependListener', 'prependOnceListener',
    'off', 'offAll', 'offOwner', 'removeAllListeners', 'removeListener',
    'emit', 'emitOwner', 'setMaxListeners', 'getMaxListeners', 'hasOwner',
    'listeners', 'listenerCount', 'eventNames', 'rawListeners'
  ];
  let DefaultMaxListeners = 10;
  /**
   * 1. An EventEmitter follows the API of NodeJS EventEmitter.
   * 2. Enhancement:
   *    * Listeners are grouped by "owner".
   *    * Operation via "owner"
   *    * Duplicate listeners are filtered out. Only unique One kept.
   */
  class EventEmitter {
    /**
     * Mixes EventEmitter methods into the given object.
     * @template T
     * @param {T} obj - The target object to mix methods into.
     * @returns {T} The modified object with EventEmitter methods.
     */
    static mixin (obj) {
      const emitter = new EventEmitter();
      // @ts-ignore
      obj.__emitter = emitter;
      for (const name of MixinMethods) {
        // @ts-ignore
        const method = emitter[name];
        // @ts-ignore
        obj[name] = method.bind(emitter);
      }
      return obj
    }

    static get defaultMaxListeners () {
      return DefaultMaxListeners
    }

    static set defaultMaxListeners (maxListeners) {
      assertNumber(maxListeners);
      DefaultMaxListeners = maxListeners ?? 10;
    }

    /**
     */
    constructor () {
      /**
       * @type {Map<string|Symbol, Event>}
       */
      this._name2Event = new Map();
      this._maxListeners = DefaultMaxListeners;
    }

    /**
     * Alias of {@linkcode EventEmitter.addListener}
     * @param {string|Symbol} eventName
     * @param {function} listener
     * @param {*} [owner]
     * @returns {this}
     */
    addListener (eventName, listener, owner) {
      return this.on(eventName, listener, owner)
    }

    /**
     * Adds the listener function to the beginning of the listeners array for the event named eventName.
     * @param {string|Symbol} eventName
     * @param {function} listener
     * @param {*} [owner]
     * @returns {this}
     */
    prependListener (eventName, listener, owner) {
      assertString(eventName);
      assertFunction(listener);
      this._checkMaxListeners(eventName);

      const event = this._getOrCreateEvent(eventName);
      event.prependListener(listener, owner);
      return this
    }

    /**
     * Adds a one-time listener function for the event named eventName to the beginning of the listeners array.
     * @param {string|Symbol} eventName
     * @param {function} listener
     * @param {*} [owner]
     * @returns {this}
     */
    prependOnceListener (eventName, listener, owner) {
      assertString(eventName);
      assertFunction(listener);
      this._checkMaxListeners(eventName);

      const event = this._getOrCreateEvent(eventName);
      event.prependOnceListener(listener, owner);
      return this
    }

    /**
     * Synchronously calls each of the listeners registered for the event named eventName,
     * in the order they were registered, passing the supplied arguments to each.
     * Returns true if the event had listeners, false otherwise.
     * @param {string|Symbol} eventName - The name of the event.
     * @param {...*} args arguments to pass to the listeners.
     * @returns {boolean}
     */
    emit (eventName, ...args) {
      const event = this._name2Event.get(eventName);
      if (event == null || event.isEmpty()) {
        return false
      }
      event.emit(...args);
      return true
    }

    /**
     * Emits an event To the specified owner.
     * @param {string} eventName - The name of the event to emit.
     * @param {any} owner - The owner of listeners
     * @param {...*} args - Additional arguments to pass with the event.
     */
    emitOwner (eventName, owner, ...args) {
      if (owner == null) {
        throw new Error('Missing "owner"')
      }
      const event = this._name2Event.get(eventName);
      if (event == null || event.isEmpty()) {
        return false
      }
      event.emitOwner(owner, ...args);
      return true
    }

    /**
     * Returns an array listing the events for which the emitter has registered listeners.
     * @returns {Array<string|Symbol>} An array of event names.
     */
    eventNames () {
      return [...this._name2Event.keys()]
    }

    getMaxListeners () {
      return this._maxListeners
    }

    /**
     * Returns the number of listeners listening for the event named eventName.
     * If listener is provided, it will return how many times the listener is found
     * in the list of the listeners of the event.
     * @param {string|Symbol} eventName - The name of the event to check
     * @param {function} [listener] - Optional specific listener to count
     * @returns {number} The number of listeners for the event
     */
    listenerCount (eventName, listener) {
      assertStringOrSymbol(eventName, 'eventName');
      const event = this._name2Event.get(eventName);
      if (event == null || event.isEmpty()) {
        return 0
      }
      return event.listenerCount(listener)
    }

    /**
     * Returns a copy of the array of listeners for the event named eventName.
     * 1. if a callback function added multiple times, it will be returned multiple times.
     * @param {string} eventName
     * @returns {Array<function>}
     */
    listeners (eventName) {
      assertStringOrSymbol(eventName, 'eventName');
      const event = this._name2Event.get(eventName);
      if (event == null || event.isEmpty()) {
        return []
      }
      return event.callbacks()
    }

    /**
     * Removes a callback function from a specific event.
     * 1. If the event doesn't exist or has no listeners, do nothing
     * 2. if one callback function added multiple times, all of them will be removed.
     *    * !!! This is different from the behavior of Node.js EventEmitter.
     *
     * @param {string} eventName - The name of the event to remove callback from
     * @param {function} callback - The callback function to remove
     * @returns {EventEmitter} Returns the emitter instance for chaining
     */
    off (eventName, callback) {
      const event = this._name2Event.get(eventName);
      if (event == null) {
        return this
      }
      event.removeListener(callback);
      if (event.isEmpty()) {
        this._name2Event.delete(eventName);
        return this
      }
      return this
    }

    /**
     * Removes all listeners for the specified event.
     * if owner is limited, only the listeners of the owner will be removed.
     *
     * @param {string|Symbol} eventName - The name of the event to clear listeners for.
     * @param {*} owner - The owner whose listeners should be removed.
     * @returns {EventEmitter} The emitter instance for chaining.
     */
    offAll (eventName, owner) {
      assertStringOrSymbol(eventName, 'eventName');
      const event = this._name2Event.get(eventName);
      if (event == null) {
        return this
      }
      event.removeAllListeners(owner);
      if (event.isEmpty()) {
        this._name2Event.delete(eventName);
        return this
      }
      return this
    }

    /**
     * Removes all event listeners belonging to the specified owner.
     * @param {*} owner - The owner whose listeners should be removed.
     * @returns {this}
     */
    offOwner (owner) {
      assertNotNil(owner, 'owner');
      const events = [...this._name2Event.values()];
      for (const event of events) {
        event.removeAllListeners(owner);
        if (event.isEmpty()) {
          this._name2Event.delete(event.name);
        }
      }
      return this
    }

    /**
     * Adds the listener function to the end of the listeners array for the event named eventName.
     * @param {string|Symbol} eventName
     * @param {function} callback
     * @param {*} [owner]
     * @returns {this}
     */
    on (eventName, callback, owner) {
      assertString(eventName);
      assertFunction(callback);
      this._checkMaxListeners(eventName);

      const event = this._getOrCreateEvent(eventName);
      event.addListener(callback, owner);
      return this
    }

    /**
     * Checks if the number of listeners for the given event exceeds the maximum allowed.
     * Emits a warning if the listener count reaches or exceeds the maxListeners threshold.
     * @private
     * @param {string|Symbol} eventName - The name of the event to check
     * @returns {void}
     */
    _checkMaxListeners (eventName) {
      let listenerCount = 0;
      if (this._maxListeners !== 0 && this._maxListeners !== Infinity && (listenerCount = this.listenerCount(eventName)) >= this._maxListeners) {
        console.warn(`maxlistenersexceededwarning: Possible EventEmitter memory leak detected. ${listenerCount} ${eventName} listeners added to [${this}]. Use emitter.setMaxListeners() to increase limit`);
      }
    }

    /**
     * Adds a listener that will be invoked only once for the event named eventName.SIGINT listeners added to [process]. Use emitter.setMaxListeners() to increase limit`)
      }
    }

    /**
     * Adds a one-time callback function for the specified event.
     * The callback is invoked only once and then automatically removed.
     *
     * @param {string} eventName - The name of the event to listen for.
     * @param {Function} callback - The callback function to execute when the event is emitted.
     * @param {*} [owner] - Optional owner used to group listener callbacks.
     * @returns {EventEmitter} Returns the emitter instance for chaining.
     */
    once (eventName, callback, owner) {
      assertString(eventName);
      assertFunction(callback);

      const event = this._getOrCreateEvent(eventName);
      event.addOnceListener(callback, owner);
      return this
    }

    /**
     * Returns a copy of the array of listeners for the event named eventName,
     * including any wrappers (such as those created by .once()).
     * @param {string} eventName - The name of the event.
     * @returns {Listener[]} An array of raw listener functions, or empty array if none exist.
     */
    rawListeners (eventName) {
      return this._name2Event.get(eventName)?.rawListeners() || []
    }

    /**
     * Alias of {@linkcode EventEmitter.offAll}
     * @param {string|Symbol} eventName - The name of the event to remove listeners for.
     * @param {*} owner - The owner of the listeners to be removed.
     * @returns {EventEmitter} The emitter instance for chaining.
     */
    removeAllListeners (eventName, owner) {
      return this.offAll(eventName, owner)
    }

    /**
     * Alias of {@linkcode EventEmitter.off}
     * @param {string} eventName - The name of the event.
     * @param {Function} callback - The callback function to remove.
     * @returns {EventEmitter} The emitter instance for chaining.
     */
    removeListener (eventName, callback) {
      return this.off(eventName, callback)
    }

    /**
     * Sets the maximum number of listeners that can be added to this event emitter.
     * @param {number} max - The maximum number of listeners.
     * @returns {this} The set maximum number of listeners.
     */
    setMaxListeners (max) {
      assertNumber(max);
      if (max < 0) {
        throw new RangeError('maxListeners must >=0')
      }
      this._maxListeners = max;
      return this
    }

    /**
     * Gets an existing event by name or creates a new one if it doesn't exist.
     * @private
     * @param {string|Symbol} eventName - The name of the event to get or create.
     * @returns {Event} The existing or newly created Event instance.
     */
    _getOrCreateEvent (eventName) {
      if (this._name2Event.has(eventName)) {
        // @ts-ignore
        return this._name2Event.get(eventName)
      }
      const event = new Event(eventName);
      this._name2Event.set(eventName, event);
      return event
    }

    /**
     * Checks if the specified owner has any registered events.
     * @param {Object} owner - The owner object to check for registered events.
     * @returns {boolean} True if the owner has any registered events, false otherwise.
     */
    hasOwner (owner) {
      if (isNil(owner)) {
        return false
      }
      for (const event of this._name2Event.values()) {
        if (event.hasOwner(owner)) {
          return true
        }
      }
      return false
    }
  }

  exports.EventEmitter = EventEmitter;
  exports.default = EventEmitter;

  Object.defineProperty(exports, '__esModule', { value: true });

}));
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