code: def char_matches(s1, s2, n=3):
      
      return __matches(s1, s2, char_ngrams, n=n)
docs: Character-level n-grams that match between two strings
  
          Args:
              s1: a string
              s2: another string
              n: an int for the n in n-gram
  
          Returns:
              set: the n-grams found in both strings