langchain/vectorstores/opensearch_vector_search.py/_approximate_search_query_with_boolean_filter
def _approximate_search_query_with_boolean_filter(
    query_vector: List[float],
    boolean_filter: Dict,
    k: int = 4,
    vector_field: str = "vector_field",
    subquery_clause: str = "must",
) -> Dict:
    """For Approximate k-NN Search, with Boolean Filter."""
    return {
        "size": k,
        "query": {
            "bool": {
                "filter": boolean_filter,
                subquery_clause: [
                    {"knn": {vector_field: {"vector": query_vector, "k": k}}}
                ],
            }
        },
    }