code: public function channelGroupDelete($cgid, $force = false)
      {
          $this->channelGroupListReset();
  
          $this->execute("channelgroupdel", array("cgid" => $cgid, "force" => $force));
      }
docs: Deletes the channel group specified with $cgid. If $force is set to 1, the channel group
  will be deleted even if there are clients within.
  
  @param  integer $sgid
  @param  boolean $force
  @return void