Given a method that must ensure that its parameter is not null：
11. public void someMethod（Object value） {
12. // check for null value
...
20. System.out.println（value.getClass（））；
21. }
What inserted at line 12， is the appropriate way to handle a null value？（）

A team of programmers is involved in reviewing a proposed design for a new utility class. After some discussion， they realize that the current design allows other classes to access methods in the utility class that should be accessible only to methods within the utility class itself.
What design issue has the team discovered？（）