code: function error(message) {
  		if (EventEmitter.listenerCount(wanted, 'error') > 0) {
  			return wanted.emit('error', message);
  		}
  
  		throw new Error(message);
  	}
docs: Trigger an error emission or throw it, depending on where a listener for error emission is present
  @name    error
  @access  internal
  @param   string  message
  @return  void