code: def _identify_gradient_grad(op, dy):
      """Gradient function for the DebugIdentity op."""
      # TODO(cais): Allow overriding gradient.
      grad_debugger_uuid, orig_tensor_name = _parse_grad_debug_op_name(
          op.name
      )
      grad_debugger = _gradient_debuggers[grad_debugger_uuid]
      grad_debugger.register_gradient_tensor(orig_tensor_name, dy)
      return dy
  
imports: import re
  import uuid
  from tensorflow.python.debug.lib import debug_data
  from tensorflow.python.debug.lib import debug_graphs
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor
  from tensorflow.python.ops import gen_array_ops
  from tensorflow.python.ops import variables
label_desc: Use image node_id 4 for calling a global function with example usage: _identify_gradient_grad(op, dy) and returns: dy