* Get random product * @returns {Promise<Object>} - Random product

* Get a random user from the database. * @returns {Promise<Object|null>} - Random user or null if no users exist

* Get all fields and values in a hash * @param {string} key - Hash key * @returns {Promise<Object|null>} - Promise resolving to an object with a

* Set multiple hash fields to multiple values * @param {string} key - Hash key * @param {Object} fields - Object containing field-value pairs

* Increment a key's value * @param {string} key - Key to increment * @returns {Promise<number|null>} - Promise resolving to the new value

* Get a range of elements from a list * @param {string} key - List key * @param {number} start - Start index * @param {number} stop - Stop in

* Remove item from cart * @param {string} userId - User ID * @param {string} itemId - Cart item ID * @returns {Promise<Object>} - Updated car

* Reset user password (after validating token externally). * @param {string} userId * @param {string} newPassword * @returns {Promise<Object>

* Push a value to the end of a list * @param {string} key - List key * @param {any} value - Value to push * @returns {Promise<number|null>} -

* Update a product by ID. * @param {string} productId - MongoDB product ID. * @param {Object} updateData - Fields to update. * @returns {Prom

* Update user fields by ID. * @param {string} userId - MongoDB user ID. * @param {Object} updateData - Fields to update. * @returns {Promise<