public class JSONObject {
    public class value {


   }



public class JSONException extends Exception {}


public class JSONTokener {
   }

    public static  testmethod void test_valueToString() {
        /*
        Make sure that the JSON rendered by this class passes validation by parsers
        from http://json.org/json2.js and http://www.jsonlint.com.
        For example:    {foo: "bar"} is invalid
                        {"foo": "bar"} is valid
        */
    }

}

getting below exception 

Error: Compile Error: Defining type for testMethod methods must be declared as IsTest at line 15 column 36


if i try adding @isTest method  end up with this error 
Compile Error: testMethod are by default IsTest at line 16 column 36

Can someone please help with this
 

I recently got Data Loader 39 and was trying to update settings for updating nulls.  I can't seem to save the settings.  I scroll to bottom of settings the screen won't go to the end and can't save.  I'm I missing a step?