had Error

[dajun512]

Json Example
{
mid: 1501,
description: "This what"
}
-----------------
@interface Episode : RLMObjec
@Property NSInteger mid;
@Property NSString *desc;

@EnD

@implementation Episode

• (NSDictionary *)JSONInboundMappingDictionary {
  return @{
  @"description": @"desc"
  };
  }

@EnD

When I used it, had error

How to convert description property;