contentA->video->set_length (3);
contentA->set_position (film, DCPTime::from_frames(2, film->video_frame_rate()));
contentA->video->set_length (3);
contentA->set_position (film, DCPTime::from_frames(2, film->video_frame_rate()));
contentB->video->set_length (1);
contentB->set_position (film, DCPTime::from_frames(7, film->video_frame_rate()));
contentB->video->set_length (1);
contentB->set_position (film, DCPTime::from_frames(7, film->video_frame_rate()));