Example:

    class Outer
    {
        private static final class Nested
        {
            private Nested(int n) { }

            public static Nested getInstance(int n)
            {
                return new Nested(n);
            }
        }
    }

The Nested class should be highlighted as unused, because there is no call to the static method getInstance() within 
the Outer class. When removing the getInstance() method definition, the Nested class is correctly highlighted as 
unused. Note that while the getInstance() method is public in Nested, it is still private in Outer because Nested is 
private in Outer. As the method is static, it's also not possible for it to be invoked through a super type.

(NB 6.7.1)