code: def add_namespace_to_graph(self, graph: BELGraph) -> Namespace:
          
          namespace = self.upload_bel_namespace()
          graph.namespace_url[namespace.keyword] = namespace.url
  
          # Add this manager as an annotation, too
          self._add_annotation_to_graph(graph)
  
          return namespace
docs: Add this manager's namespace to the graph.