code: def maybe_base_expanded_node_name(self, node_name):
      
      with self._node_name_lock:
        # Lazily populate the map from original node name to base-expanded ones.
        if self._maybe_base_expanded_node_names is None:
          self._maybe_base_expanded_node_names = dict()
          # Sort all the node names.
          sorted_names = sorted(node.name for node in self._graph_def.node)
          for i, name in enumerate(sorted_names):
            j = i + 1
            while j < len(sorted_names) and sorted_names[j].startswith(name):
              if sorted_names[j].startswith(name + '/'):
                self._maybe_base_expanded_node_names[name] = (
                    name + '/(' + name.split('/')[-1] + ')')
                break
              j += 1
        return self._maybe_base_expanded_node_names.get(node_name, node_name)
docs: Expand the base name if there are node names nested under the node.
  
      For example, if there are two nodes in the graph, "a" and "a/read", then
      calling this function on "a" will give "a/(a)", a form that points at
      a leaf node in the nested TensorBoard graph. Calling this function on
      "a/read" will just return "a/read", because there is no node nested under
      it.
  
      This method is thread-safe.
  
      Args:
        node_name: Name of the node.
        graph_def: The `GraphDef` that the node is a part of.
  
      Returns:
        Possibly base-expanded node name.