code: def get_last_doc(self):
          
  
          def docs_by_ts():
              for meta_collection_name in self._meta_collections():
                  meta_coll = self.meta_database[meta_collection_name]
                  for ts_ns_doc in meta_coll.find(limit=-1).sort("_ts", -1):
                      yield ts_ns_doc
  
          return max(docs_by_ts(), key=lambda x: x["_ts"])
docs: Returns the last document stored in Mongo.