Add BaseCombineDocumentsChain to CombineDocsChainComponent

src/backend/langflow/components/chains/CombineDocsChain.py

@@ -2,6 +2,7 @@
 from langflow import CustomComponent
 from langflow.field_typing import BaseLanguageModel, Chain
 from typing import Union, Callable
+from langchain.chains.combine_documents.base import BaseCombineDocumentsChain
 
 class CombineDocsChainComponent(CustomComponent):
     display_name = "CombineDocsChain"
@@ -24,14 +25,4 @@ class CombineDocsChainComponent(CustomComponent):
         if chain_type not in ['stuff', 'map_reduce', 'map_rerank', 'refine']:
             raise ValueError(f"Invalid chain_type: {chain_type}")
 
-        # Implement the logic to create and return the appropriate chain based on the chain_type
-        # This could be a placeholder for now, as the specific chain loading function is not defined.
-        # Replace with actual implementation when available.
-        return load_qa_chain(llm=llm, chain_type=chain_type)
-
-# Assuming there is a function or class `load_qa_chain` that creates the chain
-# based on the `chain_type` and `llm`. This is a placeholder for the actual
-# implementation which should be replaced with the correct function/class call.
-def load_qa_chain(llm: BaseLanguageModel, chain_type: str) -> Union[Chain, Callable]:
-    # Implement the logic to create and return the appropriate chain based on the chain_type
-    pass
+        return BaseCombineDocumentsChain()