def METHOD_NAME(self):
    """
    Return translated fields as list of tuples (language code, fields).
    """
    from itertools import groupby
    fields = [(field.html_name.split('__')[0], field) for field in self
              if '__' in field.html_name]
    groups = groupby(fields, lambda x: x[0])
    values = [(lang, list(map(lambda x: x[1], group)))
              for lang, group in groups]
    return values