code: def _MarkReachedOps(from_ops, reached_ops, func_graphs):
      """Mark all ops reached from "from_ops".
  
      Args:
        from_ops: list of Operations.
        reached_ops: set of Operations.
        func_graphs: list of FuncGraphs. This method will traverse through
          these functions if they capture from_ops or any reachable ops.
      """
      queue = collections.deque()
      queue.extend(from_ops)
      while queue:
          op = queue.popleft()
          if op not in reached_ops:
              reached_ops.add(op)
              for output in op.outputs:
                  if backprop_util.IsTrainable(output):
                      queue.extend(_Consumers(output, func_graphs))
  
imports: import collections
  import contextlib
  from tensorflow.core.framework import attr_value_pb2
  from tensorflow.python import pywrap_tfe
  from tensorflow.python.eager import backprop_util
  from tensorflow.python.eager import context
  from tensorflow.python.framework import composite_tensor
  from tensorflow.python.framework import composite_tensor_gradient
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import indexed_slices
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor
  from tensorflow.python.framework import tensor_shape
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import control_flow_ops
  from tensorflow.python.ops import control_flow_state
  from tensorflow.python.ops import control_flow_util
  from tensorflow.python.ops import default_gradient
  from tensorflow.python.ops import gen_functional_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import resource_variable_ops
  from tensorflow.python.ops.unconnected_gradients import UnconnectedGradients
  from tensorflow.python.platform import tf_logging
  from tensorflow.python.util import compat
  from tensorflow.python.util import object_identity
  from tensorflow.python.util import variable_utils
  from tensorflow.python.util.compat import collections_abc
  from tensorflow.python.util.tf_export import tf_export
label_desc: Use image node_id 1 for calling a global function with example usage: _MarkReachedOps(from_ops, reached_ops, func_graphs) without return types