def build_response(self, titles):
"""
Does the generic parts of building a request. Just provide a list of titles discovered by the subclass's
implementation of action_request
"""
titles_with_availability = API.find_titles(titles)
avail, unavail = self.separate_availability(titles_with_availability)
self.response = Response()
self.response.avail_titles = avail
self.response.unavail_titles = unavail
self.response.request_type = self.str_type
