langchain/vectorstores/vectara.py/Vectara/similarity_search
class Vectara:    def similarity_search(
        self,
        query: str,
        k: int = 5,
        alpha: float = 0.025,
        filter: Optional[str] = None,
        **kwargs: Any,
    ) -> List[Document]:
        """Return Vectara documents most similar to query, along with scores.

        Args:
            query: Text to look up documents similar to.
            k: Number of Documents to return. Defaults to 5.
            filter: Dictionary of argument(s) to filter on metadata. For example a
                filter can be "doc.rating > 3.0 and part.lang = 'deu'"} see
                https://docs.vectara.com/docs/search-apis/sql/filter-overview for more
                details.

        Returns:
            List of Documents most similar to the query
        """
        docs_and_scores = self.similarity_search_with_score(
            query, k=k, alpha=alpha, filter=filter, **kwargs
        )
        return [doc for doc, _ in docs_and_scores]