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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 File Identifier Descriptor.

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

        if self.len_fi > 0:
            if self.encoding == 'latin-1':
                prefix = b'\x08'
            elif self.encoding == 'utf-16_be':
                prefix = b'\x10'
            else:
                raise pycdlibexception.PyCdlibInternalError('Invalid UDF encoding; this should not happen')

            fi = prefix + self.fi
        else:
            fi = b''
        rec = struct.pack(self.FMT, b'\x00' * 16, 1,
                          self.file_characteristics, self.len_fi,
                          self.icb.record(),
                          self.len_impl_use) + self.impl_use + fi + b'\x00' * UDFFileIdentifierDescriptor.pad(struct.calcsize(self.FMT) + self.len_impl_use + self.len_fi)
        return self.desc_tag.record(rec[16:]) + rec[16:]