<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def drop_namespace_by_url(self, url: str) -> None: """Drop the namespace at the given URL. Won't work if the edge store is in use. :param url: The URL of the namespace to drop """

        namespace = self.get_namespace_by_url(url)
        self.session.query(NamespaceEntry).filter(NamespaceEntry.namespace == namespace).delete()
        self.session.delete(namespace)
        self.session.commit()