SortedHashSet Error 2

Hi some of u might have answered my previous question. Thank you. now i have these following problems.

heres my code

import java.io.*;
import java.lang.*;
import java.util.*;

class SortedHashSet<T> extends TreeSet<T> { // inherit from TreeSet
      
      private HashSet<T> hashobject;

      public SortedHashSet (){
            hashobject = new HashSet<T>(); //create new HashSet object
      }
      
      public boolean add(T item){
            return super.add(item) && hashobject.add(item);
      }
      
      
                public void clear(){
            super.clear();
            hashobject.clear();
      }
      
      public boolean contains(Object item){
            return hashobject.contains(item);
      }
      
      public boolean remove(Object item){
            return super.remove(item) && hashobject.remove(item);
      }
}

then i get the following errors

SortedHashSet.add was missing return tag.
SortedHashSet.contains was missing return tag.
SortedHashSet.remove was missing return tag.

can anyone please help me with this?