Fixed error

        sample_perm = np.arange(n_samples)

      if batch_size is None:

        batch_size = n_samples

      for epoch in epochs:

      for epoch in range(epochs):

        if not deterministic:

          sample_perm = np.random.permutation(n_samples)

        batch_idx = 0

    ds = dc.data.ImageDataset(files, np.random.random(10))

    X = ds.X

    iterated_ids = set()

    for x, y, w, ids in ds.iterbatches(2):

    for x, y, w, ids in ds.iterbatches(2, epochs=2):

      np.testing.assert_array_equal([2, 28, 28], x.shape)

      np.testing.assert_array_equal([2], y.shape)

      np.testing.assert_array_equal([2], w.shape)

      np.testing.assert_array_equal([2], ids.shape)

      for i in (0, 1):

        assert ids[i] in files

        if len(iterated_ids) < 10:

          assert ids[i] not in iterated_ids

          iterated_ids.add(ids[i])

        else:

          assert ids[i] in iterated_ids

        index = files.index(ids[i])

        np.testing.assert_array_equal(x[i], X[index])

    assert len(iterated_ids) == 10