// version 8: import lombok.experimental.ExtensionMethod; @ExtensionMethod(ExtensionMethodVarargs.Extensions.class) class ExtensionMethodVarargs { public void test() { Long l1 = 1l; long l2 = 1l; Integer i1 = 1; int i2 = 1; "%d %d %d %d".format(l1, l2, i1, i2); "%d".format(l1); "".format(new Integer[]{1,2}); "".format(new Integer[]{1,2}, new Integer[]{1,2}); } static class Extensions { public static String format(String string, Object... params) { return String.format(string, params); } } }