Source.fromCompletionStage
Deprecated by Source.completionStage.
Signature
Source.fromCompletionStageSource.fromCompletionStage
Description
fromCompletionStage has been deprecated in 2.6.0, use completionStage instead.
Send the single value of the CompletionStage when it completes and there is demand. If the CompletionStage completes with null stage is completed without emitting a value. If the CompletionStage fails the stream is failed with that exception.
Reactive Streams semantics
emits the future completes
completes after the future has completed