core-js/src/object.js

Standard library

!function(){
  function define(target, mixin){
    var keys   = ownKeys(ES5Object(mixin))
      , length = keys.length
      , i = 0, key;
    while(length > i)defineProperty(target, key = keys[i++], getOwnDescriptor(mixin, key));
    return target;
  };
  $define(STATIC + FORCED, OBJECT, {
    isObject: isObject,
    classof: classof,
    define: define,
    make: function(proto, mixin){
      return define(create(proto), mixin);
    }
  });
}();