CoreMessages implements Messages { @Override public String getMessage(@PropertyKey(resourceBundle = CORE) final String key, final Object... arguments) { return messages.getMessage(key, arguments); } CoreMessages(); @Override String getMessage(@PropertyKey(resourceBundle = CORE) final String key, final Object... arguments); @Override boolean hasMessage(final String key);  }
@Test public void getMessageShouldReturnMessageFromCoreProperties() { final String message = coreMessages.getMessage("core.settings.errorPopup.saveFailed", 20); assertEquals("Settings could not be saved:\n20", message); }