code: def test_invalid_mode(self):
      with self.assertRaisesRegex(ValueError, "Mode must be set to"):
          _ = data_providers.input_fn(
              path=testdata.GOLDEN_TRAINING_EXAMPLES,
              config=self.config,
              mode="invalid_mode",
              n_epochs=1,
          )
  
imports: import math
  from absl.testing import absltest
  from absl.testing import parameterized
  import numpy
  import tensorflow
  from tensorflow import estimator
  from deepvariant import data_providers
  from deepvariant import dv_config
  from deepvariant import dv_constants
  from deepvariant import dv_utils
  from deepvariant import testdata
  from deepvariant.protos import deepvariant_pb2
  from third_party.nucleus.io import tfrecord
  from third_party.nucleus.testing import test_utils
  from third_party.nucleus.util import variant_utils
  from tensorflow.core.example import example_pb2
label_desc: Use image node_id 2 for calling the CreateExamplesTest obj's underlying member method code with example usage: obj.test_invalid_mode() without return types