code: function enqueueEvent( self, eventItem ) {
     if( self.eventQueue_.length === 0 ) {
        self.nextTick_( () => {
           const queuedEvents = self.eventQueue_;
  
           self.eventQueue_ = [];
  
           processWaitingPublishPromises( self, processQueue( self, queuedEvents ) );
        } );
     }
     self.eventQueue_.push( eventItem );
  }
docs: ////////////////////////////////////////////////////////////////////////////////////////////////////////////