code: def check_ordered(self): 
      
      sys.stderr.write("error unimplemented check_ordered\n")
      sys.exit()
      seen_chrs = set()
      curr_chr = None
      prevstart = 0
      for l in self._lines:
        if not l['rng']: continue
        if l['rng'].chr != curr_chr:
          prevstart = 0
          if l['rng'].chr in seen_chrs:
            return False
          curr_chr = l['rng'].chr
          seen_chrs.add(curr_chr)
        if l['rng'].start < prevstart:  return False
        prevstart = l['rng'].start
      return True
docs: True if each chromosome is listed together as a chunk and if the range starts go from smallest to largest otherwise false
  
      :return: is it ordered?
      :rtype: bool