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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 verify_message(self, message):
 """Verify the checksum of the message."""

        if verify_checksum(
                message,
                self.in_checksum.get(message.id, 0),
        ):
            self.in_checksum[message.id] = message.checksum[1]

            if message.flags == FlagsType.none:
                self.in_checksum.pop(message.id)
        else:
            self.in_checksum.pop(message.id, None)
            raise InvalidChecksumError(
                description="Checksum does not match!",
                id=message.id,
            )