code: public void set(ILexLocation location, Value newval, Context ctxt)
  			throws ValueException, AnalysisException
  	{
  		abort(4088, "Set not permitted for " + kind(), ctxt);
  	}
docs: Change the object's value. Normally, values are immutable, but subclasses of {@link UpdatableValue} implement
  this set method to replace the object referenced with another. ReferenceValues like UpdatableValue delegate all
  the other Value method to the contained object.
  
  @param location
  Unused.
  @param newval
  The new value to set
  @param ctxt
  The context used
  @throws ValueException
  @throws AnalysisException