code: function checkIceGatheringState(otherPeer) {
          console.log("entered checkIceGatheringState");
          if( peerConns[otherPeer] && peerConns[otherPeer].pc && peerConns[otherPeer].pc.iceGatheringState ) {
             if( peerConns[otherPeer].pc.iceGatheringState === "complete" ) {
                 self.sendPeerMessage(otherPeer, "iceGatheringDone", {});
                 console.log("sent iceGatherDone message to ", otherPeer);
             } 
             else {
                 setTimeout( function() {
                    checkIceGatheringState(otherPeer); 
                 }, 500);
             }
          }
          else { 
             console.log("checkIceGatherState: leaving");
             // peer left, ignore
          }
      }
docs: this is a support function for halfTrickIce support. it sends a message to the peer when ice collection has finished on this side. it is only invoked for peers that have sent us a supportHalfTrickIce message.