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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 record(self):
        # type: () -> bytes
        '''
        A method to generate the string representing this UDF Entity ID.

        Parameters:
         None.
        Returns:
         A string representing this UDF Entity ID.
        '''
        if not self._initialized:
            raise pycdlibexception.PyCdlibInternalError('UDF Entity ID not initialized')

        return struct.pack(self.FMT, self.flags, self.identifier, self.suffix)