[[FastKV defaultFastKV] setBool:YES forKey:@"key"];
[[FastKV defaultFastKV] setInteger:1 forKey:@"key"];
[[FastKV defaultFastKV] setObject:@"value" forKey:@"key"];

[[FastKV defaultFastKV] boolForKey:@"key"];
[[FastKV defaultFastKV] integerForKey:@"key"];
[[FastKV defaultFastKV] objectOfClass:NSString.class forKey:@"key"];

typedef NS_ENUM(NSUInteger, FastKVMemoryStrategy) {
    FastKVMemoryStrategyDefault = 0,
    FastKVMemoryStrategy1,
};

size_t allocationSize = 1;
    while (allocationSize <= neededSize) {
        allocationSize *= 2;
    }
    return allocationSize;

size_t allocationSize = (neededSize >> 3) + (neededSize < 9 ? 3 : 6);
return allocationSize + neededSize;