connectFlagByte method
Return the connect flag value
Implementation
int connectFlagByte() =>
(reserved1 ? 1 : 0) |
(cleanStart ? 1 : 0) << 1 |
(willFlag ? 1 : 0) << 2 |
(willQos.index) << 3 |
(willRetain ? 1 : 0) << 5 |
(passwordFlag ? 1 : 0) << 6 |
(usernameFlag ? 1 : 0) << 7;