In addition to the Flux.create methods, there is a Mono.create method. This method provides a MonoSink, which can be used to generate a value, completion, or error event. Unlike the Flux methods, where we are generating N events, if we generate more events in Mono, they are dropped. There is also no handling for backpressure, as there is only one event.
The API does not take subscription cancellations into account. This means that even if the subscriber has cancelled its subscription, the create method still generates its event. Implementors must register custom hooks to lifecycle events and perform stream closures.