code: def _SymGrad(op: ops.Operation, out_grads):
      """Backprop through a function call node op given its outputs' gradients."""
      f_in = [x for x in op.inputs] + out_grads
      f_types = [default_gradient.get_zeros_dtype(x) for x in op.inputs]
      f = attr_value_pb2.NameAttrList()
      if _IsPartitionedCall(op):
          f.name = op.get_attr("f").name
      else:
          f.name = op.type
      for k in op.node_def.attr:
          f.attr[k].CopyFrom(op.node_def.attr[k])
      in_grads = gen_functional_ops.symbolic_gradient(
          input=f_in, Tout=f_types, f=f
      )
      return in_grads
  
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 9 for calling a global function with example usage: _SymGrad(op, out_grads) and returns: in_grads