public void execute(ThrowingRunnable command) {
    executor.submit((Callable<Void>) () -> {
      command.run();
      return null;
    });
  }
Executes the given command at some time in the future.

@param command the runnable task
@throws RejectedExecutionException if this task cannot be accepted for execution
@throws NullPointerException if command is null
geode-junit/src/main/java/org/apache/geode/test/junit/rules/ExecutorServiceRule.java