code: def segment_reduce_grad_op(
      self,
      data,
      segment_ids,
      reducer_grad,
      grad_out,
      output,
      indices=None,
  ):
      segments = self.split(data, segment_ids, indices)
      segment_grads = [
          reducer_grad(grad_out[i], [output[i]], [segment])
          for i, segment in enumerate(segments)
      ]
      return self.unsplit(data.shape[1:], segment_grads, segment_ids)
  
imports: from functools import partial
  from hypothesis import given, settings
  import numpy
  import unittest
  import hypothesis.strategies
  from caffe2.python import core, workspace
  import caffe2.python.hypothesis_test_util
  import caffe2.python.serialized_test.serialized_test_util
label_desc: Use image node_id 2 for calling the TesterBase obj's underlying member method code with example usage: obj.segment_reduce_grad_op(data, segment_ids, reducer_grad, grad_out, output, indices) and returns: self