NB 4.2 (200508091800)
JDK 1.5.0_04

NoSuchElementException is thrown when extracting super class from file with more
top elements.

Steps to reproduce:
1) create new file containig two classes
public class ClassA {
    public void method1(int x) { }        
}

class TopElement  {
    public void method2(int y) { }
}

2) call Extract Interface
3) type some name and confirm

-> refactoring is performed but exception is thrown in console and undo
refactoring is disabled

java.util.NoSuchElementException
        at java.util.LinkedList.getFirst(LinkedList.java:109)
        at
org.netbeans.modules.javacore.internalapi.UndoManager.addItem(UndoManager.java:267)