code: def unigrams_that_only_occur_in_one_bigram(bigrams):
      # type: (set) -> set
      tok_bigram_counts = Counter()
      for bigram in bigrams:
          for tok in bigram.split():
              tok_bigram_counts[tok] += 1
      return {
          tok for tok, count in tok_bigram_counts.items() if count == 1
      }
  
file_path: scattertext/scattertext/TermDocMatrixFilter.py
imports: from collections import Counter
  import numpy
  from scattertext.Common import DEFAULT_PMI_THRESHOLD_COEFFICIENT
label_desc: Use image node_id 3 for calling a global function with example usage: unigrams_that_only_occur_in_one_bigram(bigrams) and returns: unknown