json = JSON.parse(response.body)
    book = json['items'][0]['volumeInfo']

    language = book['language'] === 'en'? 'English' : 'unknown'
    type = book['printType'] === 'BOOK'? 'paperback' : 'unknown'
    isbn10 = get_isbn(book, 'ISBN_10')
    isbn13 = get_isbn(book, 'ISBN_13')

    return {
        'id' => id,
        'author': book['authors'][0],
        'year': book['publishedDate'],
        'type' => type,

		removed = subs.Difference(have).Difference(haveAliases).Merge(removed)
	}

	if !w.Wildcard {
		// For on-demand, we may have requested a VIP but gotten Pod IPs back. We need to update
		// the internal book-keeping to subscribe to the Pods, so that we push updates to those Pods.
		w.ResourceNames = subs.Merge(have).UnsortedList()
	} else {
		// For wildcard, we record all resources that have been pushed and not removed