4.x
4.x: Cleanup: Serial annotation, getFirst usage (#8180)
4.x: Cleanup, wording minor things (#8186)
4.x: Streamable +blockingFirst,last[OrError],skip ,S.flattenAsStreamable (#8229)
Package shift from .rxjava3 to .rxjava4
4.x: Streamable ~ separate streamer cancellation & DisposableContainer (#8223)
4.x: Streamable optimizations 2026.07.21 (#8254)