yfujiki

- (NSMutableDictionary *) mutableDeepCopy {
    NSMutableDictionary * returnDict = [[NSMutableDictionary alloc] initWithCapacity:self.count];
    NSArray * keys = [self allKeys];

    for(id key in keys) {
        id oneValue = [self objectForKey:key];
        id oneCopy = nil;

        if([oneValue respondsToSelector:@selector(mutableDeepCopy)]) {
            oneCopy = [oneValue mutableDeepCopy];