Issue 17: Unpacking does not purify invariants above root node
Project Member Reported by kevin.bi...@gmail.com, Sep 23, 2008
Invariants above the unpacked root node are not purified.
Jul 31, 2009
Project Member #1 nels.bec...@gmail.com
Kevin's last email said that he thought this was finished but the following code I 
think should have a warning:

@States({"S1","S2"})
@ClassStates(@State(name="alive", inv="full(myField)"))
@NonReentrant
public class Issue17Test {

  private Object myField;
	
  @Full(guarantee="S1", use=Use.FIELDS)
  void canICallPure() {
    needsPure(myField);
  }
	
  private static void needsPure(@Pure Object obj) {}
	
  @Full(guarantee="S1", use=Use.FIELDS)
  void canICallFull() {
    needsFull(myField); // Warning here, right?
  }
	
  private static void needsFull(@Full Object obj) {}	
}