code: def GetProb(self, hist, word):
      if (
          len(hist) >= args.ngram_order
          or not hist in self.counts[len(hist)]
      ):
          return None
      counts_for_hist = self.counts[len(hist)][hist]
      total_count = float(counts_for_hist.total_count)
      if not word in counts_for_hist.word_to_count:
          print(
              "make_phone_lm.py: no prob for {0} -> {1} "
              "[no such count]".format(hist, word),
              file=sys.stderr,
          )
          return None
      prob = float(counts_for_hist.word_to_count[word]) / total_count
      if (
          len(hist) > 0
          and word != self.backoff_symbol
          and self.backoff_symbol in counts_for_hist.word_to_count
      ):
          prob_in_backoff = self.GetProb(hist[1:], word)
          backoff_prob = (
              float(counts_for_hist.word_to_count[self.backoff_symbol])
              / total_count
          )
          try:
              prob += backoff_prob * prob_in_backoff
          except Exception:
              sys.exit(
                  "problem, hist is {0}, word is {1}".format(hist, word)
              )
      return prob
  
imports: import argparse
  import math
  import sys
  from collections import defaultdict
label_desc: Use image node_id 8 for calling the NgramCounts obj's underlying member method code with example usage: obj.GetProb(hist, word) and returns: prob, None, None