Object.extend()

extend.js

Object.defineProperty(Object.prototype, 'extend', {
  enumerable: false,
  value: function( from ) {
    Object.getOwnPropertyNames( from ).forEach(function( name ) {
      if ( name in this ) {
        Object.defineProperty( this, name, Object.getOwnPropertyDescriptor( from, name ));
      }
    });
    
    return this;
  }
});

/*
 * Usage
 */
 
obj.extend( obj2 );