priority of app_easy_timer

I would like to make priority of timer0 interruption callback higher than priority of app_easy_timer callback. Is app_easy_timer callback called by BLE_GROSSTGTIM_IRQn interruption handler? If so, is this code allowed?

NVIC_SetPriority (SWTIM_IRQn 2);

NVIC_SetPriority (BLE_GROSSTGTIM_IRQn, 3);