src/java.base/share/classes/java/util/concurrent/Joiners.java

@@ -210,10 +210,15 @@
          public boolean onComplete(Subtask<? extends T> subtask) {
              ensureCompleted(subtask);
              return isDone.test(subtask);
          }
  
+         @Override
+         public void onTimeout() {
+             // do nothing, this joiner does not throw TimeoutException
+         }
+ 
          @Override
          public Stream<Subtask<T>> result() {
              return subtasks.stream();
          }
      }