use try/expect for empty queue check
use try/expect for empty queue check

skob/alerta,0312birdzhang/alerta,mrkeng/alerta,0312birdzhang/alerta,mrkeng/alerta,guardian/alerta,guardian/alerta,0312birdzhang/alerta,mrkeng/alerta,skob/alerta,guardian/alerta,skob/alerta,guardian/alerta,skob/alerta,mrkeng/alerta