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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_ppt_segment(self, fptr):
 """Parse the PPT segment. The packet headers are not parsed, i.e. they remain "uninterpreted" raw data beffers. Parameters fptr : file object The file to parse. Returns ------- PPTSegment The current PPT segment. """

        offset = fptr.tell() - 2

        read_buffer = fptr.read(3)
        length, zppt = struct.unpack('>HB', read_buffer)
        length = length
        zppt = zppt

        numbytes = length - 3
        ippt = fptr.read(numbytes)

        return PPTsegment(zppt, ippt, length, offset)