'Returns a dict with:
- A special list (with _translations key suffix) mapping languages to
translations, to be deserialized by ESTranslationSerializerField.
- A list with all translations, intended to be analyzed and used for
searching (only included if include_field_for_search is True,
defaults to False).'

@classmethod
def extract_field_translations(cls, obj, field, db_field=None, include_field_for_search=False):

    if (db_field is None):
        db_field = ('%s_id' % field)
    extend_with_me = {('%s_translations' % field): [{'lang': to_language(lang), 'string': string} for (lang, string) in obj.translations[getattr(obj, db_field)] if string]}
    if include_field_for_search:
        extend_with_me[field] = list(set((s for (_, s) in obj.translations[getattr(obj, db_field)])))
    return extend_with_me
