Does any preparation necessary before closing the image.

None  

object.PrepareToClose

The PrepareToClose Method syntax has these parts:

Miscellaneous

This method is automatically called before any visible image is closed, so you generally will not have to call it. The image is fully functional after this call and the Collection property is undisturbed. The image may still be saved or otherwise manipulated; in fact, there is no need to close the image at all if some reason arises to cancel the pending close.

Currently the method only stops any running tool.