public class InventoryItem { public int Id { get; set; } public string Name { get; set; } public decimal Price { get; set; } public int Quantity { get; set; } } public class InventoryManager { private readonly ListIn this example, we have a class called `InventoryItem` which represents an item in the inventory. It has properties for ID, name, price, and quantity. We then have a class called `InventoryManager` which manages the inventory. It has a private field for a list of `InventoryItem` objects and a method called `AddInventoryItem` which adds an item to the list. To use this code, we would first create an instance of `InventoryManager` and then create an instance of `InventoryItem` with the desired properties. We would then pass the `InventoryItem` object to the `AddInventoryItem` method of the `InventoryManager` instance. The package library for this code is likely the default .NET standard library, as it does not appear to require any external dependencies._inventoryItems; public InventoryManager() { _inventoryItems = new List (); } public void AddInventoryItem(InventoryItem item) { _inventoryItems.Add(item); } }