gistfile1.txt

@interface __NSSpecialDictionary : NSObject
@end

@implementation __NSSpecialDictionary
@end

@interface NSDictionary (specialDictionaries)
+ (instancetype)specialDictionary;
@end

@implementation NSDictionary (specialDictionaries)

+ (instancetype)specialDictionary
{
    return [[__NSSpecialDictionary alloc] init];
}