def METHOD_NAME(self, declared_fields, info):
    # remove form self.Meta.fields, fields with suffix _<lang> get by settings
    langs = ['_'+l[0] for l in settings.LANGUAGES]
    meta_fields = getattr(self.Meta, 'fields', None)
    cleared_meta_fields = []
    if meta_fields == serializers.ALL_FIELDS:
        fields = info.fields.copy()
        for f in fields:
            if f[-3:] not in langs:
                cleared_meta_fields.append(f)
        # resetting self.Meta.fields
        self.Meta.fields = cleared_meta_fields
    return super(GetUnlanguageFieldsMixin, self).METHOD_NAME(declared_fields, info)