code: def _TensorListConcatGrad(
      op: ops.Operation, dtensor, unused_dlengths
  ):
      """Gradient function for TensorListConcat."""
      dlist = tensor_list_split(
          dtensor,
          element_shape=gen_list_ops.tensor_list_element_shape(
              op.inputs[0], shape_type=dtypes.int32
          ),
          lengths=op.outputs[1],
      )
      if op.type == "TensorListConcatV2":
          return dlist, None, None
      else:
          return dlist
  
imports: import numpy
  from tensorflow.core.framework import full_type_pb2
  from tensorflow.python.framework import cpp_shape_inference_pb2
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor
  from tensorflow.python.framework import tensor_shape
  from tensorflow.python.framework import tensor_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import gen_list_ops
  from tensorflow.python.ops import handle_data_util
  from tensorflow.python.ops.gen_list_ops import *
label_desc: Use image node_id 16 for calling a global function with example usage: _TensorListConcatGrad(op, dtensor, unused_dlengths) and returns: dlist,  None,  None, dlist