code: def setUp(self):
      super(MixedPrecisionTest, self).setUp()
      # Enable the tests to be run on pre-Volta GPUs by telling the grappler pass
      # to ignore performance and always transform the graph.
      self._original_ignore_perf_value = os.getenv(self.IGNORE_PERF_VAR)
      os.environ[self.IGNORE_PERF_VAR] = "1"
  
imports: import os
  from absl.testing import parameterized
  from tensorflow.core.protobuf import config_pb2
  from tensorflow.python.client import session
  from tensorflow.python.eager import context
  from tensorflow.python.eager import def_function
  from tensorflow.python.framework import config
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import variables
  from tensorflow.python.platform import test
  from tensorflow.python.platform import tf_logging
  from tensorflow.python.training import gradient_descent
  from tensorflow.python.training.experimental import loss_scale_optimizer
  from tensorflow.python.training.experimental import mixed_precision
  from tensorflow.python.training.experimental import mixed_precision_global_state
label_desc: Use image node_id 1 for calling the MixedPrecisionTest obj's underlying member method code with example usage: obj.setUp() without return types