function removeEventListener( event, callback ) {
    if ( !_events.hasOwnProperty( event ) ) {
      return this;
    }

    var index = _events[event].indexOf( callback );
    if ( index !== -1 ) {
      _events[event].splice( index, 1 );
    }

    return this;
  }
/**
   * Remove an added event listener.
   * Must match a call made to addEventListener.
   * @param {string} event - The event name to remove.
   * @param {Function} callback - The function attached to the event.
   * @returns {Object} The instance this EventObserver instance is decorating.
   */
Remove an added event listener.
Must match a call made to addEventListener.
@param {string} event - The event name to remove.
@param {Function} callback - The function attached to the event.
@returns {Object} The instance this EventObserver instance is decorating.
Remove an added event listener . Must match a call made to addEventListener . @param { string } event - The event name to remove . @param { Function } callback - The function attached to the event . @returns { Object } The instance this EventObserver instance is decorating .
function removeEventListener( event, callback ) {
    if ( !_events.hasOwnProperty( event ) ) {
      return this;
    }
    var index = _events[event].indexOf( callback );
    if ( index !== -1 ) {
      _events[event].splice( index, 1 );
    }
    return this;
  }
function removeEventListener ( event , callback ) { if ( ! _events . hasOwnProperty ( event ) ) { return this ; } var index = _events [ event ] . indexOf ( callback ) ; if ( index !== - 1 ) { _events [ event ] . splice ( index , 1 ) ; } return this ; }
Remove an added event listener.
Remove an added event listener .