import lombok.Functions.Function1; import lombok.Function; import lombok.Validate.NotNull; class FunctionPlain { @Function public static boolean startsWith(@NotNull String string, @NotNull String _prefix) { return string.startsWith(_prefix); } @Function public static float sqrt(float f) { return (float) Math.sqrt(f); } @Function public static <T> void notNull(T object, Function1<T, T> notNullFunction) { if (object != null) notNullFunction.apply(object); } @Function public static int[] testArrays(float[] a, double[] b) { return null; } }