clientId property
A client ID, used for identifying this client when publishing messages or for presence purposes.
The clientId can be any non-empty string, except
it cannot contain a *. This option is primarily intended to be used in
situations where the library is instantiated with a key. Note that a
clientId may also be implicit in a token used to instantiate the
library. An error will be raised if a clientId specified here conflicts
with the clientId implicit in the token.
Implementation
String? clientId;