我正在使用此代码删除redis中的redis键：

let del_result = del_redis_key(&del_key).await;
    match del_result {
        Ok(success) => {
            info!("increment delete success...")
        }
        Err(failed) => {
            let failed_data = serde_json::to_string(&failed.as_result()).unwrap();
            info!("increment delete failed...,{}",failed_data);
        }
    };

当删除redis key失败时，我想注销错误消息，但当我试图记录错误（log = "0.4"）时，编译时显示错误：

error[E0599]: no method named `as_result` found for enum `mobc_error::Error` in the current scope
  --> src/biz/music/songs_controller.rs:66:61
   |
66 |             let failed_data = serde_json::to_string(&failed.as_result()).unwrap();
   |                                                             ^^^^^^^^^ method not found in `mobc_error::Error`
   |

我应该怎么做才能注销错误信息？顺便说一句，这是删除redis键功能看起来像：

pub async fn del_redis_key(key: &str,) -> Result<()> {
    let config_redis_string = getConfig("redisConnectionStr");
    let REDIS_CON_STRING: &str = config_redis_string.as_str();
    let redis_client = redis::Client::open(REDIS_CON_STRING).expect("can create redis client");
    let mut redis_conn = get_con(redis_client);
    let mut redis_conn_unwrap = redis_conn.unwrap();
    let del_result = redis_conn_unwrap.del(key).map_err(RedisCMDError)?;
    FromRedisValue::from_redis_value(&del_result).map_err(|e| RedisTypeError(e).into())
}