Load a specific document from the given database.

        :param database: the `Database` object to retrieve the document from
        :param doc_id: the document ID
        :return: the `Document` instance, or `None` if no document with the
                 given ID was found

def load(cls, database, doc_id):
        """Load a specific document from the given database.

        :param database: the `Database` object to retrieve the document from
        :param doc_id: the document ID
        :return: the `Document` instance, or `None` if no document with the
                 given ID was found
        """
        doc = database.get(doc_id)
        if doc is None:
            return None
        return cls.wrap(doc)