code: function disposeOfSocket(apiBase) {
          return function (error) {
              loggingService.warn("Got disconnected from signalling server (" + apiBase + ")", error);
  
              var socket = connectedSockets[apiBase];
              if (socket) {
                  stopConnectivityChecks();
                  socket.removeAllListeners();
                  socket.io.removeAllListeners();
                  try {
                      socket.disconnect();
                  }
                  catch (ignore) {
                  }
                  deleteSocket(apiBase);
  
                  if (!unloadInProgress) {
                      connectAndMonitor();
                  }
              }
              else {
                  throw new Error("BUG ::: Disconnected from a socket we're not connected to?!");
              }
          };
      }
docs: Return a closure that will dispose of a socket
  
  @param apiBase
  @returns {Function}