public CompletableFuture<Void> runAsync(Runnable runnable) {
    return CompletableFuture.runAsync(runnable, executor);
  }
Returns a new CompletableFuture that is asynchronously completed by a task running in the
dedicated executor after it runs the given action.

@param runnable the action to run before completing the returned CompletableFuture
@return the new CompletableFuture
geode-junit/src/main/java/org/apache/geode/test/junit/rules/ExecutorServiceRule.java