public function getEpisodeByAirDate($serieId, $airdate, $language = null)
{
$language = $language ?: $this->defaultLanguage;
$data = $this->fetchXml('GetEpisodeByAirDate.php?apikey=' . $this->apiKey . '&seriesid=' . $serieId . '&airdate=' . $airdate . '&language=' . $language);
return new Episode($data->Episode);
}