private InventorySlot? FindSlotForItem(Item item)
{
InventorySize size = GetItemInventorySize(item);
for (int r = 0; r <= Rows - size.Height; r++)
for (int c = 0; c <= Columns - size.Width; c++)
if (CollectOverlappingItems(item, r, c) == 0)
return new InventorySlot() { Row = r, Column = c };
return null;
}