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 .