_EmptyRetriever Class — langchain Architecture

Architecture documentation for the _EmptyRetriever class in test_flare.py from the langchain codebase.

Class python

Entity Profile

Dependency Diagram

graph TD
  9f90d45c_2d11_1684_3075_65127c9c32bf["_EmptyRetriever"]
  3a20478a_3692_141f_433b_a32429b00020["BaseRetriever"]
  9f90d45c_2d11_1684_3075_65127c9c32bf -->|extends| 3a20478a_3692_141f_433b_a32429b00020
  61b72c8b_1d90_92a9_95b4_7adf79f2a9cf["test_flare.py"]
  9f90d45c_2d11_1684_3075_65127c9c32bf -->|defined in| 61b72c8b_1d90_92a9_95b4_7adf79f2a9cf
  1312f2bf_bb57_908c_b882_85b230a15ab6["_get_relevant_documents()"]
  9f90d45c_2d11_1684_3075_65127c9c32bf -->|method| 1312f2bf_bb57_908c_b882_85b230a15ab6
  2829f264_38f8_81e1_4027_7f01362b83fe["_aget_relevant_documents()"]
  9f90d45c_2d11_1684_3075_65127c9c32bf -->|method| 2829f264_38f8_81e1_4027_7f01362b83fe

Relationship Graph

Source Code

libs/langchain/tests/unit_tests/chains/test_flare.py lines 13–22

class _EmptyRetriever(BaseRetriever):
    """Minimal no-op retriever used only for constructing FlareChain in tests."""

    def _get_relevant_documents(self, query: str) -> list[Document]:  # type: ignore[override]
        del query  # mark used
        return []

    async def _aget_relevant_documents(self, query: str) -> list[Document]:  # type: ignore[override]
        del query  # mark used
        return []