class_docstr: Calculates metrics for each language given tokenization info.
code: def _get_wordpiece_overlap_percent(
      self, xx_wordpiece_counter, en_wordpiece_counter, weighted=False
  ):
      numerator = 0
      denominator = 0
      for wordpiece, count in xx_wordpiece_counter.iteritems():
          if not weighted:
              count = 1
          denominator += count
          if wordpiece in en_wordpiece_counter:
              numerator += count
  
      if denominator:
          return 100.0 * numerator / denominator
      else:
          return None
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import collections
  import apache_beam
  import tensorflow.compat.v1
  from tensorflow_text.python.ops.bert_tokenizer import BertTokenizer
  from tensorflow_text.python.ops.wordpiece_tokenizer import WordpieceTokenizer
  from tensorflow_text.tools.wordpiece_vocab import wordpiece_tokenizer_learner_lib
label_desc: Use image node_id 7 for calling the CalculateMetrics obj's underlying member method code with example usage: obj._get_wordpiece_overlap_percent(xx_wordpiece_counter, en_wordpiece_counter, weighted) and returns: unknown, None