def save(self, filename=None):
        filename = Path(filename) if filename is not None else self.filename
        with filename.open("w") as f:
            f.write(self.yaml)
def permutation_subjects(y):
    """Permute class labels of Contextual Disorder dataset.
    """
    y_perm = np.random.randint(0, 2, len(y)/2)
    y_perm = np.concatenate((y_perm, np.logical_not(y_perm).astype(int)))
    return y_perm