This event is emitted when the saver detects that the document it is
responsible for saving has changed in a way that makes it stale from the
point of view of saving.
Suppose that the document has been saved. Then a change is made. Upon this
first change, this event is emitted. Then a change is made again. Since the
document was already stale, this event is not emitted again.
This event is emitted when the saver detects that the document it is responsible for saving has changed in a way that makes it stale from the point of view of saving.
Suppose that the document has been saved. Then a change is made. Upon this first change, this event is emitted. Then a change is made again. Since the document was already stale, this event is not emitted again.