code: def _buildTemplates(self):
          
          #  in this case we only have one
          contents = self._renderTemplate(self.template_name, extraContext=None)
          # the main url used for opening viz
          f = self.main_file_name
          main_url = self._save2File(contents, f, self.output_path)
          return main_url
docs: do all the things necessary to build the viz
          should be adapted to work for single-file viz, or multi-files etc.
  
          :param output_path:
          :return: