code: public function getRev($channel = "stable")
      {
          switch ($channel) {
              case "stable":
                  return isset($this->build_datetimes[0]) ? $this->build_datetimes[0] : null;
  
              case "beta":
                  return isset($this->build_datetimes[1]) ? $this->build_datetimes[1] : null;
  
              case "alpha":
                  return isset($this->build_datetimes[2]) ? $this->build_datetimes[2] : null;
  
              case "server":
                  return isset($this->build_datetimes[3]) ? $this->build_datetimes[3] : null;
  
              default:
                  throw new Ts3Exception("invalid update channel identifier (" . $channel . ")");
          }
      }
docs: Returns the current build number for a specified update channel. Note that since version
  3.0.0, the build number represents an integer timestamp. $channel must be set to one of
  the following values:
  
  - stable
  - beta
  - alpha
  - server
  
  @param  string $channel
  @throws Ts3Exception
  @return integer