public partial class BaseInventory
{
    /// <summary>
    /// The type of the inventory in question, such as player, container, et cetera.
    /// </summary>
    [Net] public string Type { get; set; }

    /// <summary>
    /// The unique identifier of the inventory in the database.
    /// </summary>
    [Net] public long UniqueId { get; set; }

    /// <summary>
    /// The items contained by this inventory.
    /// </summary>
    [Net] public IList<ItemInstance> Items { get; set; }

    /// <summary>
    /// Returns the list of items contained within this inventory of the given type.
    /// </summary>
    /// <param name="type">The type of the item.</param>
    /// <returns>The items contained in the inventory with of given type.</returns>
    public IEnumerable<ItemInstance> GetItemsOfType( string type )
    {
        return Items.Where( item => item.Type == type );
    }

    /// <summary>
    /// Returns the list of items contained within this inventory which pass the given filter.
    /// </summary>
    /// <param name="filter">The filter that defines which items will be returned.</param>
    /// <returns>The items contained in the inventory which pass the given filter.</returns>
    public IEnumerable<ItemInstance> FilterItems( Func<ItemInstance, bool> filter )
    {
        return Items.Where( filter );
    }

    /// <summary>
    /// Checks whether or not the inventory contains an item of the given type.
    /// </summary>
    /// <param name="type">The type to look for.</param>
    /// <returns>The item if found, otherwise null.</returns>
    public ItemInstance HasItem( string type )
    {
        return GetItemsOfType( type ).FirstOrDefault();
    }

    /// <summary>
    /// Checks whether or not the inventory contains an item.
    /// </summary>
    /// <param name="item">The item to look for.</param>
    /// <returns>The item if found, otherwise null</returns>
    public ItemInstance HasItem( ItemInstance item )
    {
        return FilterItems( inventoryItem => inventoryItem.UniqueId == item.UniqueId ).FirstOrDefault();
    }

    /// <summary>
    /// Adds an item of the given type to the inventory.
    /// </summary>
    /// <param name="type">The item type to add to the inventory.</param>
    /// <returns>The created instance.</returns>
    public Task<ItemInstance> AddItem( string type )
    {
        throw new NotImplementedException();
    }

    /// <summary>
    /// Adds an item to the inventory.
    /// </summary>
    /// <param name="item">The item to add.</param>
    /// <returns>The created instance.</returns>
    public bool AddItem( ItemInstance item )
    {
        throw new NotImplementedException();
    }

    /// <summary>
    /// Removes an item from the inventory.
    /// </summary>
    /// <param name="type">The type of the item to remove</param>
    /// <param name="item">The removed item instance.</param>
    /// <returns>True if the item was successfully removed, false otherwise.</returns>
    public bool RemoveItem( string type, out ItemInstance item )
    {
        throw new NotImplementedException();
    }

    /// <summary>
    /// Removes an item from the inventory.
    /// </summary>
    /// <param name="item">The item to remove.</param>
    /// <returns>True if the item was successfully removed, false otherwise.</returns>
    public bool RemoveItem( ItemInstance item )
    {
        throw new NotImplementedException();
    }

    /// <summary>
    /// Deletes an item from the inventory.
    /// </summary>
    /// <param name="type">The type of the item to delete.</param>
    /// <returns>True if the item was successfully deleted, false otherwise.</returns>
    public bool DeleteItem( string type )
    {
        throw new NotImplementedException();
    }

    /// <summary>
    /// Deletes an item from the inventory.
    /// </summary>
    /// <param name="item">The item to delete.</param>
    /// <returns>True if the item was successfully deleted, false otherwise.</returns>
    public bool DeleteItem( ItemInstance item )
    {
        throw new NotImplementedException();
    }
}