code: def testNesterovMomentum(self):
      for dtype in self.float_types:
          with self.session(), self.test_scope():
              var0 = resource_variable_ops.ResourceVariable(
                  [0.1, 0.2], dtype=dtype
              )
              var1 = resource_variable_ops.ResourceVariable(
                  [0.3, 0.4], dtype=dtype
              )
              var0_np = np.array([0.1, 0.2], dtype=dtype)
              var1_np = np.array([0.3, 0.4], dtype=dtype)
              accum0_np = np.array([0.0, 0.0], dtype=dtype)
              accum1_np = np.array([0.0, 0.0], dtype=dtype)
              cost = 0.4 * var0 * var0 + 0.9 * var1
              global_step = resource_variable_ops.ResourceVariable(
                  array_ops.zeros([], dtypes.int32), name="global_step"
              )
              mom_op = momentum_lib.MomentumOptimizer(
                  learning_rate=0.1, momentum=0.9, use_nesterov=True
              )
              opt_op = mom_op.minimize(cost, global_step, [var0, var1])
              self.evaluate(variables.global_variables_initializer())
              for _ in range(1, 5):
                  opt_op.run()
                  (
                      var0_np,
                      accum0_np,
                  ) = self._update_nesterov_momentum_numpy(
                      var0_np, accum0_np, var0_np * 0.8, 0.1, 0.9
                  )
                  (
                      var1_np,
                      accum1_np,
                  ) = self._update_nesterov_momentum_numpy(
                      var1_np, accum1_np, 0.9, 0.1, 0.9
                  )
                  self.assertAllCloseAccordingToType(
                      var0_np, self.evaluate(var0)
                  )
                  self.assertAllCloseAccordingToType(
                      var1_np, self.evaluate(var1)
                  )
  
file_path: tensorflow/tensorflow/compiler/tests/momentum_test.py
imports: import numpy
  from tensorflow.compiler.tests import xla_test
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import resource_variable_ops
  from tensorflow.python.ops import variables
  from tensorflow.python.platform import test
  from tensorflow.python.training import momentum
label_desc: Use image node_id 3 for calling the MomentumOptimizerTest obj's underlying member method code with example usage: obj.testNesterovMomentum() without return types