docs: def get_mapping(version=1, exported_at=None, app_name=None):
      """
      Return Heroku Connect mapping for the entire project.
  
      Args:
          version (int): Version of the Heroku Connect mapping, default: ``1``.
          exported_at (datetime.datetime): Time the export was created, default is ``now()``.
          app_name (str): Name of Heroku application associated with Heroku Connect the add-on.
  
      Returns:
          dict: Heroku Connect mapping.
  
      Note:
          The version does not need to be incremented. Exports from the Heroku Connect
          website will always have the version number ``1``.
  
      """
      if exported_at is None:
          exported_at = timezone.now()
      app_name = app_name or settings.HEROKU_CONNECT_APP_NAME
      return {
          'version': version,
          'connection': {
              'organization_id': settings.HEROKU_CONNECT_ORGANIZATION_ID,
              'app_name': app_name,
              'exported_at': exported_at.isoformat(),
          },
          'mappings': [
              model.get_heroku_connect_mapping()
              for model in get_heroku_connect_models()
          ]
      }