for (let i = 0; i < numberOfThreads * 2; i++) {
promises.push(pool.execute({ test: 'test' }))
}
+ await Promise.all(promises)
// The `busy` event is triggered when the number of submitted tasks at once reach the number of fixed pool workers.
// So in total numberOfThreads + 1 times for a loop submitting up to numberOfThreads * 2 tasks to the fixed pool.
expect(poolBusy).toBe(numberOfThreads + 1)