class_docstr: Graph input tracer using depth-first search.
docstr: Trace inputs.
  
  Args:
    graph_element_name: Name of the node or an output tensor of the node, as a
      str.
  
  Raises:
    GraphTracingReachedDestination: if destination_node_name of this tracer
      object is not None and the specified node is reached.
docstr_tok: ["Trace","inputs",".","Args",":","graph_element_name",":","Name","of","the","node","or","an","output","tensor","of","the","node",",","as","a","str",".","Raises",":","GraphTracingReachedDestination",":","if","destination_node_name","of","this","tracer","object","is","not","None","and","the","specified","node","is","reached","."]
code: def trace(self, graph_element_name):
      """Trace inputs.
  
      Args:
        graph_element_name: Name of the node or an output tensor of the node, as a
          str.
  
      Raises:
        GraphTracingReachedDestination: if destination_node_name of this tracer
          object is not None and the specified node is reached.
      """
      self._depth_count += 1
  
      node_name = get_node_name(graph_element_name)
      if node_name == self._destination_node_name:
          raise GraphTracingReachedDestination()
  
      if node_name in self._skip_node_names:
          return
      if node_name in self._visited_nodes:
          return
  
      self._visited_nodes.append(node_name)
  
      for input_list in self._input_lists:
          if node_name not in input_list:
              continue
          for inp in input_list[node_name]:
              if get_node_name(inp) in self._visited_nodes:
                  continue
              self._inputs.append(inp)
              self._depth_list.append(self._depth_count)
              self.trace(inp)
  
      self._depth_count -= 1
  
imports: from tensorflow.core.framework import graph_pb2
  from tensorflow.python.framework import op_def_registry
  from tensorflow.python.platform import tf_logging
label_desc: Use image node_id 2 for calling the DFSGraphTracer obj's underlying member method code with example usage: obj.trace(graph_element_name) without return types