code: def to_zipfile(self, resource, zipfile):
          
          rpr_map = self.to_strings(resource)
          with ZipFile(zipfile, 'w') as zipf:
              for (mb_cls, rpr_string) in iteritems_(rpr_map):
                  fn = get_collection_filename(mb_cls, self.__content_type)
                  zipf.writestr(fn, rpr_string, compress_type=ZIP_DEFLATED)
docs: Dumps the given resource and all resources linked to it into the given
          ZIP file.