<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def parse(self, buf):
        '''parse a FD FDM buffer'''
        try:
            t = struct.unpack(self.pack_string, buf)
        except struct.error as msg:
            raise fgFDMError('unable to parse - %s' % msg)
        self.values = list(t)