Recovering from "Dangling reference to an invalid object." error

gistfile1.m

- (BOOL)attemptRecoveryFromPossibleCascadeDeleteRuleFailureError:(NSError *)error;
{
    // Make sure it's an unknown validation error for a managed object
    if ([error code] != NSManagedObjectValidationError) return NO;
    if (![[error domain] isEqualToString:NSCocoaErrorDomain]) return NO;
    
    NSManagedObject *object = [[error userInfo] objectForKey:NSValidationObjectErrorKey];
    if (![object isKindOfClass:[NSManagedObject class]]) return NO;
    
    NSString *key = [[error userInfo] objectForKey:NSValidationKeyErrorKey];
    if (!key) return NO;
    
    // Make sure it's a relationship to another MO
    NSRelationshipDescription *relationship = [[[object entity] relationshipsByName] objectForKey:key];
    if (!relationship) return NO;
    
    // Has the target MO been deleted?
    NSManagedObject *invalidValue = [object valueForKey:key];
    if (![invalidValue isDeleted] && [invalidValue managedObjectContext]) return NO;
    
    // Should deleting that have caused the problematic object to have been deleted too?
    if ([[relationship inverseRelationship] deleteRule] != NSCascadeDeleteRule) return NO;
    
    // OK, we're pretty sure the cascade delete rule wasn't honoured, so do it ourselves
    NSLog(@"Deleting object that looks like Cascade delete rule for key %@ wasn't honoured: %@", key, object);
    [[object managedObjectContext] deleteObject:object];
    return YES;
}

@mikeabdullah : Where we have to use this method or what is the best place to write this code?