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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(cls, fptr, offset, length):
 """Parse data entry URL box. Parameters fptr : file Open file object. offset : int Start position of box in bytes. length : int Length of the box in bytes. Returns ------- DataEntryURLbox Instance of the current data entry URL box. """

        num_bytes = offset + length - fptr.tell()
        read_buffer = fptr.read(num_bytes)
        data = struct.unpack_from('>BBBB', read_buffer)
        version = data[0]
        flag = data[1:4]

        url = read_buffer[4:].decode('utf-8').rstrip(chr(0))
        return cls(version, flag, url, length=length, offset=offset)