def __init__(self,
                 dataset=None,
                 batch_size=None,
                 num_batches=None,
                 data_specs=False,
                 return_tuple=False,
                 rng=None):

        self._hmdb_iterator = HMDBIterator(dataset._hmdb, batch_size,
                                           num_batches, data_specs,
                                           return_tuple, rng)

        self._dvd_iterator = AtousaDatasetIterator(dataset._dvd, batch_size,
                                                   num_batches, data_specs,
                                                   return_tuple, rng)
        self.num_examples = self._hmdb_iterator.num_examples + self._dvd_iterator.num_examples
        self.cur = 0
        self.batch_size = batch_size
        self.dataset = dataset
        self.hmdb_stop = False
        self.dvd_stop = False