### Question:
Preconditions { public static void checkArgument(boolean expression, @Nullable ErrorCode message) { if (!expression) { throw new NulsRuntimeException(message); } }  static void checkArgument(boolean expression, @Nullable ErrorCode message); static void checkNotNull(Object object, @Nullable ErrorCode message); static void checkNotEmpty(Object object, @Nullable ErrorCode message); static void checkNotNull(Object[] objects, @Nullable ErrorCode message);  }### Answer:
@Test public void checkArgument() { }