anchor.diff:      // Check methods
   
       Map<String, MethodDeclaration> getters = <String, MethodDeclaration>{};
  -    Map<String, MethodDeclaration> setters = <String, MethodDeclaration>{};
  +    List<MethodDeclaration> setters = <MethodDeclaration>[];
   
       // Non-getters/setters.
       List<MethodDeclaration> methods = <MethodDeclaration>[];
  
positive.code:           if (member.isGetter) {
              getters[member.name.name] = member;
            } else if (member.isSetter) {
              setters[member.name.name] = member;
            } else {
              functions.add(member);
            }
  
negative.code:     }
  
      // Check all getters, and collect offenders along the way.
      Set<FunctionDeclaration> missingDocs = Set<FunctionDeclaration>();
      for (FunctionDeclaration getter in getters.values) {
        if (check(getter)) {
          missingDocs.add(getter);
  