????

SimpleObject<String> stringObject = new StringObject<String>();

SimpleObject<String> stringObject = new StringObject<>();

public class Solution {
    public static void main(String[] args) throws Exception {
        SimpleObject<String> stringObject = new StringObject<>();
    }

    interface SimpleObject<T> {
        SimpleObject<T> getInstance();
    }
     public static class StringObject<String> implements SimpleObject<String> {
        public StringObject<String> getInstance(){
            return this;
        }
    }

}

public StringObject<String> getInstance(){
            return this;
}

public static class StringObject<String> implements SimpleObject<String> {
       public SimpleObject<String> getInstance(){
           return this;
       }

private static class StringObject<T> implements SimpleObject<String> {
        @Override
        public SimpleObject<String> getInstance() {
            return null;
        }
}