async addServerEvents_(newServerEvents) {
    if (newServerEvents.length == 0) {
      return;
    }
    if (newServerEvents[0].serverId != this.lastSync + 1) {
      newServerEvents = await this.queryDatabase_();
    }
    this.lastSync = newServerEvents[newServerEvents.length - 1].serverId;
    this.serverEvents.push.apply(this.serverEvents, newServerEvents);
    this.updateWorkspace_();
  }
Add newServerEvents to the end of this.serverEvents and initiate process of
applying server events to the workspace if the newServerEvents are recieved
in the correct order.
@param {<!Array.<!Entry>>} newServerEvents The events recieved from the
server.
@throws Throws an error if newServerEvents are not recieved in the correct
order.
@private