class_docstr: Test all-reduce vs. single-reduce plus broadcast in one session.run.
class_docstr_tok: ["Test","all-reduce","vs.","single-reduce","plus","broadcast","in","one","session.run","."]
code: def testCombined(self):
      self._Test(self._Combined, lambda x, y: x + y)
  
imports: from functools import partial
  import numpy
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import ops
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import gradients
  from tensorflow.python.ops import nccl_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 2 for calling the CombinedTest obj's underlying member method code with example usage: obj.testCombined() without return types