code: def setUp(self):
      super().setUp()
      self._orig_factories = xb._backend_factories
      xb._backend_factories = {}
      self.enter_context(config.jax_platforms(""))
      self._save_backend_state()
      self._reset_backend_state()
  
      # get_backend logic assumes CPU platform is always present.
      self._register_factory("cpu", 0)
  
imports: import os
  import platform
  import time
  import warnings
  from absl import logging
  from absl.testing import absltest
  from jax._src import compiler
  from jax._src import config
  from jax._src import test_util
  from jax._src import xla_bridge
  from jax._src.interpreters import xla
  from jax._src.lib import xla_client
label_desc: Use image node_id 2 for calling the GetBackendTest obj's underlying member method code with example usage: obj.setUp() without return types