docs: def adjacent(self,rng2):
      """ Test for adjacency.  
  
      :param rng2:
      :param use_direction: false by default
      :param type: GenomicRange
      :param type: use_direction
      """
      if self.chr != rng2.chr: return False
      if self.direction != rng2.direction and use_direction: return False
      if self.end == rng2.start-1:  return True
      if self.start-1 == rng2.end: return True
      return False