CompletableFuture.thenComposeAsync stack

Thread [pool-1-thread-1] (Suspended)
    Unsafe.park(boolean, long) line: not available [native method]
    LockSupport.park(Object) line: 175
    CompletableFuture$WaitNode.block() line: 271
    ForkJoinPool.managedBlock(ForkJoinPool$ManagedBlocker) line: 3226
    CompletableFuture<T>.waitingGet(boolean) line: 319
    CompletableFuture<T>.access$000(CompletableFuture, boolean) line: 111
    CompletableFuture$AsyncCompose<T,U>.exec() line: 616
    CompletableFuture$AsyncCompose<T,U>(CompletableFuture$Async).run() line: 428
    ThreadPoolExecutor.runWorker(ThreadPoolExecutor$Worker) line: 1142
    ThreadPoolExecutor$Worker.run() line: 617
    Thread.run() line: 745