Solution Context

SolutionContext.m

- (NSManagedObjectContext *)masterManagedObjectContext {
    
    NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
    if (coordinator != nil) {
        _masterManagedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
        [_masterManagedObjectContext setPersistentStoreCoordinator:coordinator];
    }
    return _masterManagedObjectContext;
}

- (NSManagedObjectContext *)mainManagedObjectContext {
   
    _mainManagedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
    [_mainManagedObjectContext setParentContext:self.masterManagedObjectContext];
    return _mainManagedObjectContext;
}

+ (NSManagedObjectContext *)temporaryWorkerContext {
   
    NSManagedObjectContext *tempMOContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
    tempMOContext.parentContext = _mainManagedObjectContext;
    return tempMOContext;
}