def METHOD_NAME(self, old_password, new_password):
    '''
    Change the password of the current user.
    :devportal:`session: password <session-password>`
    Args:
        old_password (str): The current password.
        new_password (str): The new password.
    Returns:
        :obj:`None`:
            The password has been successfully changed.
    Examples:
        >>> tio.session.change_password('old_pass', 'new_pass')
    '''
    self._api.put('session/chpasswd', json={
        'password': self._check('new_password', new_password, str),
        'current_password': self._check('old_password', old_password, str)
    })