This policy causes a save to fail if there are any merge conflicts.
In the case of failure, the save method returns with an error with a userInfo dictionary that contains the key @"conflictList"; the corresponding value is an array of conflict records.
Available in Mac OS X v10.4 and later.
Declaration Syntax Version Information- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)