class_docstr: Test cases for unary operators.
class_docstr_tok: ["Test","cases","for","unary","operators","."]
code: def testSigmoidNumericalStability(self):
      for dtype in self.float_types:
          if dtype != np.float16:
              self._assertOpOutputMatchesExpected(
                  lambda x: math_ops.sigmoid(x)
                  / math_ops.log1p(math_ops.exp(x)),
                  np.array([-40, 40], dtype=dtype),
                  expected=np.array([1.0, 0.025], dtype=dtype),
              )
  
imports: import platform
  import unittest
  import numpy
  import six
  from tensorflow.compiler.tests import xla_test
  from tensorflow.python.framework import dtypes
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import array_ops_stack
  from tensorflow.python.ops import bitwise_ops
  from tensorflow.python.ops import gen_functional_ops
  from tensorflow.python.ops import gen_nn_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import nn_ops
  from tensorflow.python.platform import googletest
label_desc: Use image node_id 10 for calling the UnaryOpsTest obj's underlying member method code with example usage: obj.testSigmoidNumericalStability() without return types