def _detect_vector_format(self, collection_name: str) -> None:
        """
        Detect the vector format of an existing collection.
        This allows backward compatibility with collections that were created before
        the refactoring to use named vectors consistently.
        """
        try:
            collection_info = self._client.get_collection(collection_name)
            vectors_config = collection_info.config.params.vectors

            # Check if we have an unnamed vector format (where name is empty string)
            if isinstance(vectors_config, dict):
                # Using named vectors format
                if LEGACY_UNNAMED_VECTOR in vectors_config:
                    self._legacy_vector_format = True
                    self.dense_vector_name = LEGACY_UNNAMED_VECTOR
            else:
                # Using unnamed vector format from earlier versions
                self._legacy_vector_format = True
                self.dense_vector_name = LEGACY_UNNAMED_VECTOR

        except Exception as e:
            logger.warning(
                f"Could not detect vector format for collection {collection_name}: {e}"
            )

        Detect the vector format of an existing collection.
        This allows backward compatibility with collections that were created before
        the refactoring to use named vectors consistently.
        
llama-index-integrations/vector_stores/llama-index-vector-stores-qdrant/llama_index/vector_stores/qdrant/base.py