code: def Tags(self):
      
      return {
          TENSORS: list(self.tensors_by_tag.keys()),
          # Use a heuristic: if the metagraph is available, but
          # graph is not, then we assume the metagraph contains the graph.
          GRAPH: self._graph is not None,
          META_GRAPH: self._meta_graph is not None,
          RUN_METADATA: list(self._tagged_metadata.keys())
      }
docs: Return all tags found in the value stream.
  
      Returns:
        A `{tagType: ['list', 'of', 'tags']}` dictionary.