in data/custom_dataset_data_loader.py [0:0]
def CreateDataset(opt):
    dataset = None
    if opt.model == 'audioVisual':
        from data.audioVisual_dataset import AudioVisualDataset
        dataset = AudioVisualDataset()
    else:
        raise ValueError("Dataset [%s] not recognized." % opt.model)
    print("dataset [%s] was created" % (dataset.name()))
    dataset.initialize(opt)
    return dataset