Returns linguist lookup kwargs (related to Translation model).

def get_translation_kwargs(self, kwargs):
        """
        Returns linguist lookup kwargs (related to Translation model).
        """
        lks = []
        for k, v in six.iteritems(kwargs):
            if self.is_linguist_lookup(k):
                lks.append(
                    utils.get_translation_lookup(self.model._linguist.identifier, k, v)
                )

        translation_kwargs = {}
        for lk in lks:
            for k, v in six.iteritems(lk):
                if k not in translation_kwargs:
                    translation_kwargs[k] = v

        return translation_kwargs