class_docstr: unigram/bigram LM, add-k smoothing
docstr: prob of seeing words w1 w2 next to each other.
docstr_tok: ["prob","of","seeing","words","w1","w2","next","to","each","other","."]
code: def getBigramProb(self, w1, w2):
      "prob of seeing words w1 w2 next to each other."
      w1 = w1.lower()
      w2 = w2.lower()
      val1 = self.bigrams.get(w1)
      if val1 != None:
          val2 = val1.get(w2)
          if val2 != None:
              return val2
          return self.addK / (
              self.getUnigramProb(w1) * self.numUniqueWords
              + self.numUniqueWords
          )
      return 0
  
file_path: calamari/calamari_ocr/thirdparty/ctcwordbeamsearch/LanguageModel.py
imports: from __future__ import division
  from __future__ import print_function
  import re
  from .PrefixTree import PrefixTree
label_desc: Use image node_id 9 for calling the LanguageModel obj's underlying member method code with example usage: obj.getBigramProb(w1, w2) and returns: int, unknown, val2