Build: NetBeans IDE Dev (Build 200910291407)
VM: Java HotSpot(TM) Client VM, 14.1-b02, Java(TM) SE Runtime Environment, 1.6.0_15-b03
OS: Windows XP, 5.1, x86

Steps to reproduce:
- Copy the code to the editor:
----------------------------------------------------------------------------------------------------------------------------
import java.lang.Comparable;

def INFINITY = Number.MAX_VALUE;

public function sign(y:Number):Integer {
    if( y <0 ) { -1 } else if(0 < y) { 1 } else { 0 }
}

class DVertex extends Comparable{

    //var vertex:Vertex;

    var value:Number;
    var previous:Integer;

    override function compareTo(obj:Object):Integer{
            var vertex = obj as DVertex;
            return sign(value - vertex.value);
    }

}

class Vertex{}
class Edge{}
class Graph{  var vertices:Vertex[] }

public function dijkstraShortestPath(source:Vertex, destination:Vertex, graph:Graph):Edge[]{


    var vertices = for(v in graph.vertices) DVertex{
        previous: indexof v
        value: if( v == source) then  0  else INFINITY
    };

    return [];
}
------------------------------------------------------------------------------

Stacktrace: 
java.lang.AssertionError
        at org.netbeans.modules.javafx.refactoring.impl.RenameRefactoringElement.init(RenameRefactoringElement.java:274)
        at org.netbeans.modules.javafx.refactoring.impl.RenameRefactoringElement.<init>(RenameRefactoringElement.java:99)
        at org.netbeans.modules.javafx.refactoring.impl.RenameRefactoringElement.create(RenameRefactoringElement.java:78)
        at
org.netbeans.modules.javafx.refactoring.impl.plugins.RenameRefactoringPlugin.prepare(RenameRefactoringPlugin.java:390)
        at org.netbeans.modules.refactoring.api.AbstractRefactoring.pluginsPrepare2(AbstractRefactoring.java:419)
        at org.netbeans.modules.refactoring.api.AbstractRefactoring.pluginsPrepare(AbstractRefactoring.java:403)