protected function flowStart()
    {
        $this->flowMap->incrementFlow('num_exec')->flowStart();
        $this->listActiveEvent(!$this->hasParent())->triggerEvent(FlowEvent::FLOW_START);
        // flow started status kicks in after Event start to hint eventual children
        // this way, root flow is only running when a record hits a branch
        // and triggers a child flow flowStart() call
        $this->flowStatus = new FlowStatus(FlowStatus::FLOW_RUNNING);

        return $this;
    }