def _resolve_field(self, path):
    for dt in self._doc_type:
        if (not hasattr(dt, '_index')):
            continue
        field = dt._index.resolve_field(path)
        if (field is not None):
            return field
def _resolve_field(self, path):
    for dt in self._doc_type:
        if (not hasattr(dt, '_index')):
            continue
        field = dt._index.resolve_field(path)
        if (field is not None):
            return field