RestKit：映射nsnumber

Question

目前NSNumber被映射到字符串，例如：

@interface Blah：NSObject

@property NSNumber * num;

@end

将被映射到 {     num：“5” }

而不是 {     数量：5 }

有谁知道如何正确地将NSNumber映射到int，而不是字符串？

更新

RKObjectMapping *requestMapping = [RKObjectMapping requestMapping];
[requestMapping addAttributeMappingsFromArray:@[@"num"]];

RKRequestDescriptor *requestDescriptor = [RKRequestDescriptor requestDescriptorWithMapping:requestMapping objectClass:[MyClass class] rootKeyPath:nil method:RKRequestMethodPOST];

[_manager addRequestDescriptor:requestDescriptor];