try { ClassUtils.getPackageName((String) null); fail(); } catch (IllegalArgumentException ex) {} try { ClassUtils.getPackageName(""); fail(); } catch (IllegalArgumentException ex) {}
assertEquals("", ClassUtils.getPackageName((String)null)); assertEquals("", ClassUtils.getPackageName(""));
    public void test_getPackageName_String() {        assertEquals("org.apache.commons.lang", ClassUtils.getPackageName(ClassUtils.class.getName()));        assertEquals("java.util", ClassUtils.getPackageName(Map.Entry.class.getName()));        try {            ClassUtils.getPackageName((String) null);            fail();        } catch (IllegalArgumentException ex) {}        try {            ClassUtils.getPackageName("");            fail();        } catch (IllegalArgumentException ex) {}    }