public class Assert { public static void notFalse(boolean flag, String message) { if (!flag) { System.out.println(message); throw new IllegalArgumentException(); } } public static void notFalse(boolean flag) { if (!flag) { System.out.println("Failed notFalse Assertion"); throw new IllegalArgumentException(); } } public static void notNull(Object obj, String message) { if (obj == null) { System.out.println(message); throw new IllegalArgumentException(); } } public static void notNull(Object obj) { if (obj == null) { System.out.println("Failed notNull Assertion"); throw new IllegalArgumentException(); } } }