code: def demo_template_statistics():
      """
      Show aggregate statistics per template. Little used templates are
      candidates for deletion, much used templates may possibly be refined.
  
      Deleting unused templates is mostly about saving time and/or space:
      training is basically O(T) in the number of templates T
      (also in terms of memory usage, which often will be the limiting factor).
      """
      postag(incremental_stats=True, template_stats=True)
  
imports: import os
  import pickle
  import random
  import time
  from nltk.corpus import treebank
  from nltk.tag import BrillTaggerTrainer, RegexpTagger, UnigramTagger
  from nltk.tag.brill import Pos, Word
  from nltk.tbl import Template, error_list
label_desc: Use image node_id 7 for calling a global function with example usage: demo_template_statistics() without return types