Retrieve the metadata for a specific item in this ItemGroup

        :type item_index: int
        :param item_index: the index of the item
        :type force_download: Boolean
        :param force_download: True to download from the server
            regardless of the cache's contents

        :rtype: Item
        :returns: the metadata, as an Item object

        :raises: APIError if the API request is not successful

def get_item(self, item_index, force_download=False):
        """ Retrieve the metadata for a specific item in this ItemGroup

        :type item_index: int
        :param item_index: the index of the item
        :type force_download: Boolean
        :param force_download: True to download from the server
            regardless of the cache's contents

        :rtype: Item
        :returns: the metadata, as an Item object

        :raises: APIError if the API request is not successful


        """
        return self.client.get_item(self.item_urls[item_index], force_download)