### Question:
LocalizedAssert { public <T> T assertNull(T o, String argument) { if (o != null) { throwException(DBMessages.ASSERT_NULL, argument); } return o; } LocalizedAssert(final ConnectorMessages cm);  LocalizedAssert(final ConnectorMessages cm, boolean localizeArguments); T assertNotNull(T o, String argument); T assertNull(T o, String argument); String assertNotBlank(String o, String argument); String assertBlank(String s, String argument);  }### Answer:
@Test public final void testAssertNull() { Integer i = testee.assertNull(null, "i"); Assert.assertNull(i); try { i = testee.assertNull(new Integer(1), "i"); Assert.fail("Must fail for not null argument"); } catch (RuntimeException e) { Assert.assertEquals("Argument [i] must be null", e.getMessage()); } }