code: function(room) {
          this.rooms[room.roomId] = room;
          // add listeners for room member changes so we can keep the room member
          // map up-to-date.
          room.currentState.on("RoomState.members", this._onRoomMember.bind(this));
          // add existing members
          const self = this;
          room.currentState.getMembers().forEach(function(m) {
              self._onRoomMember(null, room.currentState, m);
          });
      }
docs: Store the given room.
  @param {Room} room The room to be stored. All properties must be stored.