Returns a Boolean value indicating whether the receiver should keep the backup files created before document data is written to a file (NO by default).
Original signature is '- (BOOL)keepBackupFile'
Available in Mac OS X v10.0 and later.


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