docstr: Test get_config and from_config methods.
docstr_tok: ["Test","get_config","and","from_config","methods","."]
code: def test_get_config_from_config(self):
      """Test get_config and from_config methods."""
      policy = DTypePolicy("mixed_float16")
      config = policy.get_config()
      self.assertEqual(config, {"name": "mixed_float16"})
  
      new_policy = DTypePolicy.from_config(config)
      self.assertEqual(new_policy.name, "mixed_float16")
  
imports: from keras.mixed_precision import DTypePolicy
  from keras.mixed_precision import dtype_policy
  from keras.mixed_precision import set_dtype_policy
  from keras.testing import test_case
label_desc: Use image node_id 9 for calling the DTypePolicyTest obj's underlying member method code with example usage: obj.test_get_config_from_config() without return types