code: def min_count(self, n=1):
      
      word_count = {w:c for w,c in iteritems(self.word_count) if c >= n}
      return CountedVocabulary(word_count=word_count)
docs: Returns a vocabulary after eliminating the words that appear < `n`.
  
      Args:
        n (integer): specifies the minimum word frequency allowed.