code: def testFiniteGradientAtDifficultPoints(self):
      for dtype in [np.float32, np.float64]:
          g = ops.Graph()
          with g.as_default():
              mu = variables.Variable(dtype(0.0))
              sigma = variables.Variable(dtype(1.0))
              dist = normal_lib.Normal(loc=mu, scale=sigma)
              x = np.array(
                  [-100.0, -20.0, -5.0, 0.0, 5.0, 20.0, 100.0]
              ).astype(dtype)
              for func in [
                  dist.cdf,
                  dist.log_cdf,
                  dist.survival_function,
                  dist.log_survival_function,
                  dist.log_prob,
                  dist.prob,
              ]:
                  value = func(x)
                  grads = gradients_impl.gradients(value, [mu, sigma])
                  with self.session(graph=g):
                      self.evaluate(
                          variables.global_variables_initializer()
                      )
                      self.assertAllFinite(value)
                      self.assertAllFinite(grads[0])
                      self.assertAllFinite(grads[1])
  
imports: import importlib
  import math
  import numpy
  from tensorflow.python.eager import backprop
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor_shape
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import gradients_impl
  from tensorflow.python.ops import nn_ops
  from tensorflow.python.ops import variables
  from tensorflow.python.ops.distributions import kullback_leibler
  from tensorflow.python.ops.distributions import normal
  from tensorflow.python.platform import test
  from tensorflow.python.platform import tf_logging
label_desc: Use image node_id 14 for calling the NormalTest obj's underlying member method code with example usage: obj.testFiniteGradientAtDifficultPoints() without return types