code: function _isReactKeyDown( event ) {
     return event &&
      typeof event === 'object' &&
      event.nativeEvent instanceof window.KeyboardEvent &&
      event.type === 'keydown';
  }
docs: _isReactKeyDown
  
  @access private
  @param {object} event The possibly synthetic event passed as an argument with
  the method invocation.
  @return {boolean}