message: add flatten microbenchmarks
diff: @@ -1484,6 +1484,19 @@ class MicroBenchmarks(benchmarks_test_base.MicroBenchmarksBase):
  self._run(fn, 10000)
  + def benchmark_tf_nest_flatten_none(self):
  + def fn():
  + nest.flatten(None)
  +
  + self._run(fn, 100000)
  +
  + def benchmark_tf_nest_flatten(self):
  + nested = {"a": [1, 2, 3], "b": (4, 5, 6)}
  + def fn():
  + nest.flatten(nested)
  +
  + self._run(fn, 100000)
  +
  def benchmark_tf_nn_convolution_overhead(self):
  inputs = array_ops.ones((1, 1, 1, 1))
  filters = array_ops.ones((1, 1, 1, 1))
  