'string', 'copyright_creation_time' => 'datetime', 'download_hd_url' => 'string', 'duration_in_sec' => 'float', 'id' => 'string', 'iswc' => 'string', 'metadata' => 'Object', 'published_time' => 'datetime', 'thumbnail_url' => 'string', 'title' => 'string', 'universal_content_id' => 'string', 'writer_names' => 'list', ); } }