class_docstr: Data object to store counts of various parameters during training
class_docstr_tok: ["Data","object","to","store","counts","of","various","parameters","during","training"]
code: def update_null_generation(self, count, alignment_info):
      m = len(alignment_info.trg_sentence) - 1
      fertility_of_null = alignment_info.fertility_of_i(0)
      self.p1 += fertility_of_null * count
      self.p0 += (m - 2 * fertility_of_null) * count
  
imports: from bisect import insort_left
  from collections import defaultdict
  from copy import deepcopy
  from math import ceil
label_desc: Use image node_id 3 for calling the Counts obj's underlying member method code with example usage: obj.update_null_generation(count, alignment_info) without return types