[Editor] How to use System.Collections.Generic in a UnityScript Editor Script

Hi. I'd like to know how to get System.Collections.Generic to work in my editor scripts. I use Generic Lists all the time in normal scripts, but I can get them to work in editor scripts. For example where should the "import System...." go?

 @CustomEditor(BezierSegmentScript)
 @CanEditMultipleObjects
 import System.Collections.Generic; //this line causes a compile error! Where should it go?
 
 public class BezierSegmentEditorScript extends Editor {
     
     override function OnInspectorGUI () {
         DrawDefaultInspector();
             var segmentSelectList : IList = new List.<GameObject>();
                 ...
     }
 }

Thank you for your help!