Harrison/redis id key (#2057)

Co-authored-by: Fabrizio Ruocco <ruoccofabrizio@gmail.com>

langchain/vectorstores/redis.py

@@ -62,11 +62,13 @@ class Redis(VectorStore):
     ) -> List[str]:
         # `prefix`: Maybe in the future we can let the user choose the index_name.
         prefix = "doc"  # prefix for the document keys
+        keys = kwargs.get("keys")
 
         ids = []
         # Check if index exists
         for i, text in enumerate(texts):
-            key = f"{prefix}:{uuid.uuid4().hex}"
+            _key = keys[i] if keys else uuid.uuid4().hex
+            key = f"{prefix}:{_key}"
             metadata = metadatas[i] if metadatas else {}
             self.client.hset(
                 key,