First, Dr. Jones can check for guards – obvious reasons that one wouldn’t want to do the refactoring.
	In this case, Dr. Jones can check for name conflicts, and that you’re not trying to move a constructor.
	Also a different set of rules apply for move method if the source and target classes are related by inheritance.
	Note that these`guards’ don’t completely check that the refactoring preserves the program’s behavior (since that would involve much more difficult analyses).
	Rather these are more like sanity checks to help the programmer avoid refactoring mistakes.
	(Dr. Jones can remind the programmer to check the more difficuly safety conditions when it’s time to implement the refactorings.  This runs the risk, however, of allowing the programmer to plan unsafe refactorings with Dr. Jones.)