Thrown when a attempting to use a TestObject and the underlying object in the
software under test (SUT) has been disposed. For example, in HTML if you have gotten a registered
object by calling TestObject.getParent() or TestObject.find() and then you cause
the HTML page to change, the HTML objects on the unloaded page are all disposed.
Most further attempts to use these TestObjects will cause this exception. Note that
you can and should still call unregister() on the TestObject.