@umbraco-ui/uui-base/lib/events/UUIEvent.d.ts

This is a base dependency for Umbraco UI components. It contains mixins, animations, abstract base classes, UUIEvent base class, and universal types for properties shared by different components

/**
 * Umbraco UI implementation of native DOM CustomEvent that propagates out of Shadow DOM context.
 */
export declare class UUIEvent<DetailType extends Record<string, any> = Record<string, any>, EventTargetType extends EventTarget | null = EventTarget | null> extends Event {
    readonly detail: DetailType;
    readonly target: EventTargetType;
    constructor(evName: string, eventInit?: any | null);
}