def _build_index_from_nodes(
        self,
        nodes: Sequence[BaseNode],
        show_progress: bool = False,
        **build_kwargs: Any,
    ) -> IndexList:
        """
        Build the index from documents.

        Args:
            documents (List[BaseDocument]): A list of documents.

        Returns:
            IndexList: The created summary index.

        """
        index_struct = IndexList()
        nodes_with_progress = get_tqdm_iterable(
            nodes, show_progress, "Processing nodes"
        )
        for n in nodes_with_progress:
            index_struct.add_node(n)
        return index_struct

        Build the index from documents.

        Args:
            documents (List[BaseDocument]): A list of documents.

        Returns:
            IndexList: The created summary index.

        
llama-index-core/llama_index/core/indices/list/base.py