Flow.flattenOptional

Collect the value of Optional from all the elements passing through this flow , empty Optional is filtered out.

Signature

Streams the elements through the given future flow once it successfully completes. If the future fails the stream is failed.

Emits when the current Optional’s value is present.

Backpressures when the value of the current Optional is present and downstream backpressures.

Completes when upstream completes.

Cancels when downstream cancels.