docs: def _load_bundle_map(self):
          '''
          Return a map of all bundles in the Clarify app that have an external_id set for them.
          The bundles with external_ids set are assumed to be the ones we have inserted from Brightcove.
          The external_id contains the Brightcove video id.
          '''
          bundle_map = {}
          next_href = None
          has_next = True
  
          while has_next:
              bundles = self.clarify_client.get_bundle_list(href=next_href, embed_items=True)
              items = get_embedded_items(bundles)
              for item in items:
                  bc_video_id = item.get('external_id')
                  if bc_video_id is not None and len(bc_video_id) > 0:
                      bundle_map[bc_video_id] = item
              next_href = get_link_href(bundles, 'next')
              if next_href is None:
                  has_next = False
          return bundle_map