HMSetAsync("hKey", null) on HMSetAsync throw NullException

[HenrykBudzinski]

using (var redisClient =
    RedisClient.ConnectAsync(
        "data source=127.0.0.1:6379;initial catalog=1",
        new BasicRedisSerializer()).Result)
    {
        var setState = 
            redisClient.HMSetAsync(
                "key.1", 
                new MSetArgs[] {
                    new MSetArgs("prop1", null),
                    new MSetArgs("prop2", null),
                    new MSetArgs("prop3", null)
                }).Result;
                var delState = redisClient.DelAsync("key.1").Result;
    }

Supposedly this should be turned into a BasicRedisSerializer.Null right? There is a if (value == null) return Null; and if (value == null || value.SequenceEqual(Null)) return null; on Serialize and Deserialize methods.