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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 _parse_cme_segment(self, fptr):
 """Parse the CME marker segment. Parameters fptr : file Open file object. Returns ------- CMESegment The current CME segment. """

        offset = fptr.tell() - 2

        read_buffer = fptr.read(4)
        data = struct.unpack('>HH', read_buffer)
        length = data[0]
        rcme = data[1]
        ccme = fptr.read(length - 4)

        return CMEsegment(rcme, ccme, length, offset)