async setPresenceHandlers(connectUserHandler, getUserDisconnectsHandler) {
    this.getUserDisconnects = getUserDisconnectsHandler;
    await connectUserHandler(this.workspaceId);
  }
Set handlers that enable the detection of user presence on the workspace
and send workspaceId to the server.
@param {!Function} connectUserHandler The callback that sends workspaceId to
the server.
@param {!Function} getUserDisconnectsHandler The callback that allows the
workspace to detect user disconnects.
@public