public void waitForDisplay() {
        PrimeSelenium.wait(getShowDelay());
        PrimeSelenium.waitGui().until(PrimeExpectedConditions.visibleAndAnimationComplete(this));
    }
Wait for the client side setTimeout when displaying overlay.
primefaces-selenium/primefaces-selenium-components/src/main/java/org/primefaces/selenium/component/OverlayPanel.java