package pk1; 
  
 public class MyQ { 
     protected MyItem head; 
     protected MyItem tail; 
  
     public void add(MyItem t) { } 
     public MyItem remove() { return null; } 
 } 
 

 
 package pk1; 
  
 public class MyItem { 
     // TODO 
 } 
 

 
 package pk2; 
  
 import pk1.*; 
  
 public class UniqMyQ extends MyQ { 
     @Override 
     public void add(MyItem t) { 
         MyItem s = head; 
         // TODO 
     } 
  
     @Override 
     public MyItem remove() { 
         MyItem s = head; 
         return null;  // TODO 
     } 
  
     public void uniq(UniqMyQ otherq) { 
         MyItem s = otherq.head; 
         // TODO 
     } 
  
     /* UniqMyQ is-a MyQ olmasina ragmen bu neden hatali? 
     public void uniq(MyQ otherq) { 
         MyItem s = otherq.head; 
         // TODO 
     } */ 
      
 } 
 

Let C be the class in which a protected member is declared. Access is permitted only within the body of a subclass S of C. 
  
 In addition, if Id denotes an instance field or instance method, then: 
  
 If the access is by a qualified name Q.Id or a method reference expression Q :: Id (§15.13), where Q is an ExpressionName, then the access is permitted if and only if the type of the expression Q is S or a subclass of S. 
  
 If the access is by a field access expression E.Id, or a method invocation expression E.Id(...), or a method reference expression E :: Id, where E is a Primary expression (§15.8), then the access is permitted if and only if the type of E is S or a subclass of S. 
  
 If the access is by a method reference expression T :: Id, where T is a ReferenceType, then the access is permitted if and only if the type T is S or a subclass of S.