Fix client creation error

autogen/agentchat/contrib/retrieve_user_proxy_agent.py

@@ -361,7 +361,7 @@ def retrieve_docs(self, problem: str, n_results: int = 20, search_string: str =
         """
         if not self._collection or self._get_or_create:
             print("Trying to create collection.")
-            create_vector_db_from_dir(
+            self._client = create_vector_db_from_dir(
                 dir_path=self._docs_path,
                 max_tokens=self._chunk_token_size,
                 client=self._client,

autogen/retrieve_utils.py

@@ -291,7 +291,7 @@ def create_vector_db_from_dir(
     embedding_model: str = "all-MiniLM-L6-v2",
     embedding_function: Callable = None,
     custom_text_split_function: Callable = None,
-):
+) -> API:
     """Create a vector db from all the files in a given directory, the directory can also be a single file or a url to
         a single file. We support chromadb compatible APIs to create the vector db, this function is not required if
         you prepared your own vector db.
@@ -311,6 +311,9 @@ def create_vector_db_from_dir(
         embedding_function (Optional, Callable): the embedding function to use. Default is None, SentenceTransformer with
             the given `embedding_model` will be used. If you want to use OpenAI, Cohere, HuggingFace or other embedding
             functions, you can pass it here, follow the examples in `https://docs.trychroma.com/embeddings`.
+
+    Returns:
+        API: the chromadb client.
     """
     if client is None:
         client = chromadb.PersistentClient(path=db_path)
@@ -348,6 +351,7 @@ def create_vector_db_from_dir(
             )
     except ValueError as e:
         logger.warning(f"{e}")
+    return client
 
 
 def query_vector_db(