docs: function (connectionId) {
    if (_.has(userObservesForConnections, connectionId)) {
      var observe = userObservesForConnections[connectionId];
      if (observe === null) {
        // We're in the process of setting up an observe for this
        // connection. We can't clean up that observe yet, but if we
        // delete the null placeholder for this connection, then the
        // observe will get cleaned up as soon as it has been set up.
        delete userObservesForConnections[connectionId];
      } else {
        delete userObservesForConnections[connectionId];
        observe.stop();
      }
    }
  }