use get_key;
use key_exist;
use Connection;
/**
* Securely retrieves a key from Redis if it exists.
*
* This function first checks if the key exists in Redis.
* If the key exists, it retrieves the value associated with the key.
* If the key does not exist, it returns a Redis error indicating that the key does not exist.
*
* # Arguments
* * `conn` - A mutable reference to the Redis connection.
* * `key` - The key to retrieve from Redis.
*
* # Returns
* * `Ok(String)` - The value associated with the key if it exists.
* * `Err(redis::RedisError)` - An error if the key does not exist or if there is an issue with the Redis connection.
*/
pub async