anchor.diff:    Token position() => null;
   
     Token findMyName(Token token) {
  -    for (Token t = token; t !== EOF_TOKEN; t = t.next) {
  +    for (Token t = token; t.kind !== EOF_TOKEN; t = t.next) {
         if (t.value == name) return t;
       }
       return token;
  
positive.code:   void forEachInstanceField([void f(ClassElement enclosingClass, Element field),
                               includeBackendMembers = false,
                               includeSuperMembers = false]) {
      // Filters so that [f] is only invoked with instance fields. 
      void fieldFilter(ClassElement enclosingClass, Element member) {
        if (member.isInstanceMember() && member.kind == ElementKind.FIELD) {
          f(enclosingClass, member);
  
negative.code:         }
        }
        classElement = includeSuperMembers ? classElement.superclass : null;
      } while(classElement !== null);
    }
  
    /**
  