TypeVars.java

public class TypeVars<K, V> {
    private void test(K key, V value) {
        String s = "Negative size: " + key + "=" + value;
    }

    class MyClass<T> {
        public T myMethod() {
            return null;
        }
    }

    public class TypeVarDefaults {
        class ImplicitUpperBound<T> {}

        class ExplicitUpperBound<T extends Object> {}

        void useImplicit() {
            ImplicitUpperBound<Object> bottom;
        }

        void useExplicit() {
            ExplicitUpperBound<Object> bottom;
        }

        void wildCardImplicit() {
            ImplicitUpperBound<?> bottom;
        }

        void wildCardExplicit() {
            ExplicitUpperBound<?> bottom;
        }

        void wildCardUpperBoundImplicit() {
            ImplicitUpperBound<? extends Object> bottom;
        }

        void wildCardUpperBoundExplicit() {
            ExplicitUpperBound<? extends Object> bottom;
        }

        void wildCardLowerImplicit() {
            ImplicitUpperBound<? super Object> bottom;
        }

        void wildCardLowerBoundExplicit() {
            ExplicitUpperBound<? super Object> bottom;
        }
    }
}