Implemented by subclasses to expand or reduce the top or bottom end of the selection downward by one element, character, or line (whichever is appropriate for text direction).
Original signature is '- (void)moveDownAndModifySelection:(id)sender'
Available in Mac OS X v10.0 and later.


- sender (Id)
- Typically the object that invoked this method.

- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)