code: def segment_reduce_op(self, data, segment_ids, reducer, indices=None):
      segments = self.split(data, segment_ids, indices)
      output = np.zeros((len(segments),) + data.shape[1:])
      for i, segment in enumerate(segments):
          if len(segment) > 0:
              output[i] = reducer(segment)
          else:
              output[i] = 0.0
      return output
  
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 1 for calling the TesterBase obj's underlying member method code with example usage: obj.segment_reduce_op(data, segment_ids, reducer, indices) and returns: output