Can RestKit connect a relationship without storing the foreign key as an attribute, i.e., directly from the keypath in the JSON?

In particular, I've got a Job has_many Rooms relationship. The room's JSON doesn't contain the job, rather, both are loaded separately:

- job: {
    id: 1,
    name: "John"
}

- room: {
    id: 4,
    job_id: 1,
    name: "spare bedroom"
}

The Job is loaded before the Room.

My CoreData models, Job has properties for 

@interface Job : NSManagedObject
@property (nonatomic, retain) NSNumber * identifier;
@property (nonatomic, retain) NSString * name;
@property (nonatomic, retain) NSSet *rooms;
@end

@interface Room : NSManagedObject
@property (nonatomic, retain) NSNumber * identifier;
@property (nonatomic, retain) NSString * name;
@property (nonatomic, retain) Job *job;
@end

Currently I add a @property (nonatomic, strong) NSNumber *jobID; to Room, which I @synthesize.

JobMapping:
    mapping = [RKManagedObjectMapping mappingForClass:[Job class]];
    [mapping setPrimaryKeyAttribute:@"identifier"];

    [mapping mapAttributes:@"name", nil];
    [mapping mapKeyPath:@"id" toAttribute:@"identifier"];

    [mapping mapRelationship:@"rooms" withMapping:[Room objectMapping]];



RoomMapping
    mapping = [RKManagedObjectMapping mappingForClass:[Room class]];
    [mapping setPrimaryKeyAttribute:@"identifier"];

    [mapping mapAttributes:@"name", nil];
    [mapping mapKeyPath:@"id" toAttribute:@"identifier"];
    [mapping mapKeyPath:@"job_id" toAttribute:@"jobID"];

    [mapping mapRelationship:@"job" withMapping:[Job objectMapping]];

    [mapping connectRelationship:@"job" withObjectForPrimaryKeyAttribute:@"jobID"];

I was wondering if there's a way I can do this without the extra jobID property? I don't want to have a jobID attribute in the CoreData xcdatamodeld - it's redundant, as th

core-data restkit
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