### Question:
i18n { private i18n () { } private  i18n(); static String msg( String key, Object... args );  }### Answer:
@Test public void testI18N () { assertEquals ( "Wrong message returned by the messaging API!", "This is a constant message", i18n.msg ( "test.msg.1" ) ); assertEquals ( "Wrong message returned by the messaging API!", "This a parameterized message, param value = 223", i18n.msg ( "test.msg.2", 223 ) ); assertEquals ( "Wrong message returned by the messaging API!", "Another parameterized message with the \"foo\" variable in the middle", i18n.msg ( "test.msg.3", "foo" ) ); assertTrue ( "Wrong message returned by the messaging API!", i18n.msg ( "test.msg.4" ).contains ( "__INVALID_MSG_KEY" ) ); }