import java.time.Duration;
import org.infinispan.functional.EntryView.*;
import org.infinispan.functional.FunctionalMap.*;
import org.infinispan.functional.MetaParam.*;

WriteOnlyMap<String, String> writeOnlyMap = ...
ReadOnlyMap<String, String> readOnlyMap = ...

CompletableFuture<Void> writeFuture = writeOnlyMap.eval("key1", "value1",
   (v, view) -> view.set(v, new MetaLifespan(Duration.ofHours(1).toMillis())));
CompletableFuture<MetaLifespan> readFuture = writeFuture.thenCompose(r ->
   readOnlyMap.eval("key1", view -> view.findMetaParam(MetaLifespan.class).get()));
readFuture.thenAccept(System.out::println);