FailWithMessage
FailWithMessage("Expected %c for property %s, but found %c",
FailWithMessage("Expected '%s' for property %s, but found '%s'",
FailWithMessage("Expected %" B_PRId32
FailWithMessage("Couldn't find property %s", name);
FailWithMessage("Expected type %.4s for property %s, but found %.4s",
FailWithMessage("Expected %" B_PRId32 " items for property %s, but found %" B_PRId32,