Encode a chat link for an item (or a stack of items).

    :param item_id: the Id of the item
    :param number: the number of items in the stack
    :param skin_id: the id of the skin applied to the item
    :param upgrade1: the id of the first upgrade component
    :param upgrade2: the id of the second upgrade component

def encode_item_link(item_id, number=1, skin_id=None,
                     upgrade1=None, upgrade2=None):
    """Encode a chat link for an item (or a stack of items).

    :param item_id: the Id of the item
    :param number: the number of items in the stack
    :param skin_id: the id of the skin applied to the item
    :param upgrade1: the id of the first upgrade component
    :param upgrade2: the id of the second upgrade component
    """
    return encode_chat_link(gw2api.TYPE_ITEM, id=item_id, number=number,
                            skin_id=skin_id, upgrade1=upgrade1,
                            upgrade2=upgrade2)