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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 append_data(self, len_tag, val_tag, data, header=False):
 """Append raw data, possibly including a embedded SOH. :param len_tag: Tag number for length field. :param val_tag: Tag number for value field. :param data: Raw data byte string. :param header: Append to header if True; default to body. Appends two pairs: a length pair, followed by a data pair, containing the raw data supplied. Example fields that should use this method include: 95/96, 212/213, 354/355, etc."""


        self.append_pair(len_tag, len(data), header=header)
        self.append_pair(val_tag, data, header=header)
        return