code: def test_quantization_config_num_buckets(self):
      with self.assertRaisesRegex(ValueError, "num_buckets"):
          tpu_embedding_v2_utils.QuantizationConfig(0, -1, 1)
  
imports: from absl.testing import parameterized
  from tensorflow.core.protobuf.tpu import tpu_embedding_configuration_pb2
  from tensorflow.python.compat import v2_compat
  from tensorflow.python.platform import test
  from tensorflow.python.tpu import tpu_embedding_v2_utils
label_desc: Use image node_id 3 for calling the ConfigTest obj's underlying member method code with example usage: obj.test_quantization_config_num_buckets() without return types