@classmethod
def build_from_mongo(cls, data, partial=False, use_cls=False):
    """
        Create a document instance from MongoDB data

        :param data: data as retrieved from MongoDB
        :param use_cls: if the data contains a ``_cls`` field,
            use it determine the Document class to instanciate
        """
    if use_cls and '_cls' in data:
        cls = cls.opts.instance.retrieve_document(data['_cls'])
    doc = cls()
    doc.from_mongo(data, partial=partial)
    return doc
