jax="false"
                                 value="Throw ViewExpiredException!" styleClass="mr-2"/>
                <!-- NullPointerException has no specific error-page defined in web.xml compared to ViewExpiredException -->
                <!-- https://github.com/primefaces/primefaces/blob/master/primefaces-showcase/src/main/webapp/WEB-INF/web.xml -->
                <p:commandButton action="#{exceptionHandlerView.throwNullPointerException}"
                                 ajax="false"
                  