    @Test
    public void testNameIsValid() {

        assertTrue(CustomerManagerEJB.nameIsValid("Jan"));
        assertFalse(CustomerManagerEJB.nameIsValid("Jan1"));
        assertTrue(CustomerManagerEJB.nameIsValid("Jan-Piet"));
        assertFalse(CustomerManagerEJB.nameIsValid("Jan_Piet"));
        assertTrue(CustomerManagerEJB.nameIsValid("gefräßig"));
    }