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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_namespace_entry(self, url: str, name: str) -> Optional[NamespaceEntry]: """Get a given NamespaceEntry object. :param url: The url of the namespace source :param name: The value of the namespace from the given url's document """

        entry_filter = and_(Namespace.url == url, NamespaceEntry.name == name)
        result = self.session.query(NamespaceEntry).join(Namespace).filter(entry_filter).all()

        if 0 == len(result):
            return

        if 1 < len(result):
            log.warning('result for get_namespace_entry is too long. Returning first of %s', [str(r) for r in result])

        return result[0]