Construct a map-reduce chain that uses the chain for map and reduce.
from_params(
cls,
llm: BaseLanguageModel,
prompt: BasePromptTemplate,
text_splitter: TextSplitter,
callbacks: Callbacks = None,
combine_chain_kwargs: Mapping[str, Any] | None = None,
reduce_chain_kwargs: Mapping[str, Any] | None = None,
**kwargs: Any = {}
) -> MapReduceChain