code: def get_matching_blocks(self):
          
          if self.matching_blocks is not None:
              return self.matching_blocks
  
          matching_blocks = _cdifflib.matching_blocks(self)
          matching_blocks.append((len(self.a), len(self.b), 0))
          self.matching_blocks = matching_blocks
  
          return map(_Match._make, self.matching_blocks)
docs: Same as SequenceMatcher.get_matching_blocks, but calls through to a
          faster loop for find_longest_match.  The rest is the same.