langchain/vectorstores/supabase.py/SupabaseVectorStore/similarity_search
class SupabaseVectorStore:    def similarity_search(
        self, query: str, k: int = 4, **kwargs: Any
    ) -> List[Document]:
        vectors = self._embedding.embed_documents([query])
        return self.similarity_search_by_vector(vectors[0], k)