code: def dissimilarity_metric(self, a, b):
          
          # if self._is_pylib(a) and self._is_pylib(b):
          #     return 1
  
          res = 4
          for an, bn, n in zip_longest(a.name_parts, b.name_parts, list(range(4))):
              res -= an == bn
              if n >= 3:
                  break
          return res
docs: Return non-zero if references to this module are strange, and
             should be drawn extra-long. The value defines the length, in
             rank. This is also good for putting some vertical space between
             seperate subsystems.
  
             Returns an int between 1 (default) and 4 (highly unrelated).