WorkerFactory.php
public function createWorkerPool($implementationClassName, $workerCount = null)
    {
        return WorkerPool::withClass($this->bootstrapProfile, $implementationClassName, $workerCount);
    }
public function createWorkerPool($implementationClassName, $workerCount = null)
    {
        return WorkerPool::withClass($this->bootstrapProfile, $implementationClassName, $workerCount);
    }
@param string   $implementationClassName
@param int|null $workerCount

@throws Exception\InvalidArgumentException
@throws Exception\RuntimeException

@return WorkerPool