diff --git a/packages/jupyter-ai/jupyter_ai/history.py b/packages/jupyter-ai/jupyter_ai/history.py
index ec007a8ce..fbc7d5934 100644
--- a/packages/jupyter-ai/jupyter_ai/history.py
+++ b/packages/jupyter-ai/jupyter_ai/history.py
@@ -1,14 +1,13 @@
 import time
 from typing import List, Optional, Sequence, Set, Union
 
+from jupyterlab_chat.ychat import YChat
 from langchain_core.chat_history import BaseChatMessageHistory
 from langchain_core.messages import AIMessage, BaseMessage, HumanMessage
 from langchain_core.pydantic_v1 import BaseModel, PrivateAttr
 
-from jupyterlab_chat.ychat import YChat
-
-from .models import HumanChatMessage
 from .constants import BOT
+from .models import HumanChatMessage
 
 HUMAN_MSG_ID_KEY = "_jupyter_ai_human_msg_id"
 
@@ -18,10 +17,11 @@ class YChatHistory(BaseChatMessageHistory):
     An implementation of `BaseChatMessageHistory` that yields the last `k`
     exchanges (`k * 2` messages) from the given YChat model.
     """
+
     def __init__(self, ychat: YChat, k: Optional[int]):
         self.ychat = ychat
         self.k = k
-    
+
     @property
     def messages(self) -> List[BaseMessage]:
         """Returns the last `k` messages."""
@@ -40,16 +40,16 @@ def messages(self) -> List[BaseMessage]:
                 messages.append(HumanMessage(content=message["body"]))
 
         return messages
-    
+
     def add_message(self, message: BaseMessage) -> None:
         # do nothing when other LangChain objects call this method, since
         # message history is maintained by the `YChat` shared document.
         return
-    
+
     def clear(self):
         raise NotImplementedError()
-    
-    
+
+
 class BoundedChatHistory(BaseChatMessageHistory, BaseModel):
     """
     An in-memory implementation of `BaseChatMessageHistory` that stores up to