def __iter__(self):
for train_mask, test_mask in LeaveOneLabelOut.__iter__(self):
n_test = test_mask.sum()
sub_mask = np.ones(n_test, dtype=np.bool)
sub_mask[: n_test / 2] = False
new_test_mask = test_mask.copy()
new_test_mask[test_mask] = sub_mask
train_mask[test_mask] = np.logical_not(sub_mask)
yield train_mask, new_test_mask
new_test_mask[test_mask] = np.logical_not(sub_mask)
train_mask[test_mask] = sub_mask
yield train_mask, new_test_mask
