/**
  * Create a new Round object.
  * @param number the number of this round of matches
  * @param Entity\LeagueImpl the league that the round belongs to
  * @return a new Round object instance
  * @throws RDException in case the number is not positive
  */
 public function createRound($number = null, $league = null)
 {
     $aRound = new Entity\RoundImpl();
     if ($number != null && $league != null) {
         $aRound->setNumber($number);
         $aRound->setLeague($league);
     }
     return $aRound;
 }