code: def _pair_npmi(pair, accumulator):
      """Compute normalized pairwise mutual information (**NPMI**) between a pair of words.
  
      Parameters
      ----------
      pair : (int, int)
          The pair of words (word_id1, word_id2).
      accumulator : :class:`~gensim.topic_coherence.text_analysis.InvertedIndexAccumulator`
          Word occurrence accumulator from probability_estimation.
  
      Return
      ------
      float
          NPMI between a pair of words.
  
      """
      return log_ratio_measure([[pair]], accumulator, True)[0]
  
file_path: gensim/gensim/topic_coherence/indirect_confirmation_measure.py
imports: import itertools
  import logging
  import numpy
  import scipy.sparse
  from gensim.topic_coherence.direct_confirmation_measure import aggregate_segment_sims, log_ratio_measure
label_desc: Use image node_id 3 for calling a global function with example usage: _pair_npmi(pair, accumulator) and returns: log_ratio_measure