ManagedExecutor create(String displayName, int fixedSize) {
        // Ignores size of thread pool
        return new TestManagedExecutor(executor)
    }

    @Override
    ManagedThreadPoolExecutor createThreadPool(String displayName, int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit timeUnit) {
        throw new UnsupportedOperationException()
    }

    @Override

     *        will wait for new tasks before terminating.
     * @param timeUnit the time unit for the {@code keepAliveTime} argument
     * @return The executor.
     */
    ManagedThreadPoolExecutor createThreadPool(String displayName, int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit timeUnit);

    /**

        executors.add(executor);
        return executor;
    }

    @Override
    public ManagedThreadPoolExecutor createThreadPool(String displayName, int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit timeUnit) {

                // Ignores size of thread pool
                return new ManagedExecutorStub(ConcurrentTestUtil.this)
            }

            @Override
            ManagedThreadPoolExecutor createThreadPool(String displayName, int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit timeUnit) {
                throw new UnsupportedOperationException()
            }

            @Override