1  #import <Foundation/NSObject.h>
 2  
 3  @interface NSMergePolicy : NSObject
 4  
 5  @end
 6  
 7  extern id NSErrorMergePolicy;
 8  extern id NSMergeByPropertyStoreTrumpMergePolicy;
 9  extern id NSMergeByPropertyObjectTrumpMergePolicy;
10  extern id NSOverwriteMergePolicy;
11  extern id NSRollbackMergePolicy;