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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def check_ordered(self):
 """ 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 """

    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