having problems creating a textAsset - unity editor scripting

ok, so my idea is to simply create an empty .txt file in the assets folder. ive tried using the c# system.io but to no avail, so i figured id try using unity's built in textasset - still no luck. whenever i run the script i get a "NullReferenceException" on the line that creates the file, but idk where the problem is.

any help would be greatly appreciated :D

 using UnityEngine;
 using UnityEditor;
 using System.Collections;
 using System.IO;
 
 public class SceneItem : Editor {
 
     [MenuItem( "Test UI/this is a test" )]
     public static void OpenMenu() {
     
     }
 
     [MenuItem("Test UI/submenu test/create asset")]
     static void OpenSubMenu() {
         var textFileToBeCreated = new TextAsset();
         AssetDatabase.CreateAsset(textFileToBeCreated, "Assets/NewObject.txt");
         AssetDatabase.Refresh();
 
     }
 
 }