code: def testRougeLOp_alphaValues(self):
      hyp = ragged_factory_ops.constant([[1, 2]], dtype=dtypes.int32)
      ref = ragged_factory_ops.constant([[2, 3]], dtype=dtypes.int32)
      text_similarity_metric_ops.rouge_l(hyp, ref, alpha=-1)
      text_similarity_metric_ops.rouge_l(hyp, ref, alpha=0)
      text_similarity_metric_ops.rouge_l(hyp, ref, alpha=0.5)
      text_similarity_metric_ops.rouge_l(hyp, ref, alpha=1)
      with self.assertRaises(ValueError):
          text_similarity_metric_ops.rouge_l(hyp, ref, alpha=1.00001)
  
file_path: text/tensorflow_text/python/metrics/text_similarity_metric_ops_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import re
  from absl.testing import parameterized
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops.ragged import ragged_factory_ops
  from tensorflow.python.platform import test
  from tensorflow_text.python.metrics import text_similarity_metric_ops
label_desc: Use image node_id 4 for calling the TextSimilarityMetricOpsTest obj's underlying member method code with example usage: obj.testRougeLOp_alphaValues() without return types