4.x
4.x: Streamable optimizations 2026.07.21 (#8254)
4.x: Java Migration; records, newer API, newer syntax (#8187)
4.x: Streamable Ops: doOnNext, intercept, lift, to; test cleanup (#8209)
4.x: Cleanup: Serial annotation, getFirst usage (#8180)
4.x: Fix consumer retention in cache() upon subscribe-cancel race (#8283)
4.x: Fix SchedulerToExecutorService invokeAll and invokeAny impl (#8205)
4.x: Cleanup, wording minor things (#8186)
4.x: Streamable + doOnError, forEach(StreamerInput) (#8218)
4.x: Streamable ~ separate streamer cancellation & DisposableContainer (#8223)