def __init__(
        self,
        indices: List[BaseIndex],
        retriever_modes: INDEX_SPECIFIC_QUERY_MODES_TYPE = DEFAULT_MODES,
    ):
        """
        Initialize with indices to experiment with.

        Args:
            indices: A list of BaseIndex's to experiment with
            retriever_modes: A list of retriever_modes that specify which nodes are
                chosen from the index when a query is made. A full list of
                retriever_modes available to each index can be found here:
                https://docs.llamaindex.ai/en/stable/module_guides/querying/retriever/retriever_modes.html

        """
        self._validate_indices(indices)
        self._indices = indices
        self._validate_modes(retriever_modes)
        self._retriever_modes = retriever_modes

        index_range = [str(i) for i in range(len(indices))]
        self.index_colors = get_color_mapping(index_range)

        Initialize with indices to experiment with.

        Args:
            indices: A list of BaseIndex's to experiment with
            retriever_modes: A list of retriever_modes that specify which nodes are
                chosen from the index when a query is made. A full list of
                retriever_modes available to each index can be found here:
                https://docs.llamaindex.ai/en/stable/module_guides/querying/retriever/retriever_modes.html

        
llama-index-core/llama_index/core/playground/base.py