单项选择题
Given a method that must ensure that its parameter is not null： What， inserted at line 12， is the appropriate way to handle a null value？（）
A.assert value == null； B.assert value != null ： "value is null"； C.if （value == null）{ throw new AssertionException（"value is null"）； } D.if （value == null）{ throw new IllegalArgumentException（"value is null"）； }
多项选择题 Which two code fragments are most likely to cause a StackOverflowError？（）
单项选择题 What is the result？（）
