Perform diff on two iterables containing lines from two files, and return
    the diff as as string. Lines are normalized to str types to avoid issues
    with unicode on PY2.

def get_diff(a, b, *args, **kwargs):
    '''
    Perform diff on two iterables containing lines from two files, and return
    the diff as as string. Lines are normalized to str types to avoid issues
    with unicode on PY2.
    '''
    encoding = ('utf-8', 'latin-1', __salt_system_encoding__)
    # Late import to avoid circular import
    import salt.utils.data
    return ''.join(
        difflib.unified_diff(
            salt.utils.data.decode_list(a, encoding=encoding),
            salt.utils.data.decode_list(b, encoding=encoding),
            *args, **kwargs
        )
    )