    @Test(expected = ElementNotFound_Exception.class)
    public void testGetElementByAtomicNumber_ElementNotFound() throws ElementNotFoundException, ElementNotFound_Exception {

        com.example.periodictable.ElementNotFoundException ex = new ElementNotFoundException("");

        when(periodicTableService.getElementByAtomicNumber(2)).thenThrow(ex);
        
        Element element = periodicTableWS.getElementByAtomicNumber(2);
    }