code: def _hasGPU(self):
      physical_devices = tf.config.experimental.list_physical_devices(
          "GPU"
      )
      return physical_devices
  
imports: import functools
  import itertools
  from absl import flags
  from absl.testing import parameterized
  from jax import lax
  import numpy
  import tensorflow.compat.v2
  from trax.tf_numpy import extensions
  import trax.tf_numpy.numpy
label_desc: Use image node_id 2 for calling the ExtensionsTest obj's underlying member method code with example usage: obj._hasGPU() and returns: physical_devices