corrected the type hints for StockAnalyst.get_stock_analyses method

src/stock_analysis_agent.py

@@ -5,7 +5,7 @@ from IPython.display import Image, display
 import json
 from langgraph.graph import StateGraph, START  # , END
 from langchain_openai import ChatOpenAI
-from langchain_core.messages import SystemMessage  #, AIMessage, HumanMessage
+from langchain_core.messages import SystemMessage, AIMessage, HumanMessage, ToolMessage
 from langchain_core.tools import tool
 from langgraph.prebuilt import ToolNode, tools_condition
 from langgraph.graph.message import add_messages
@@ -199,7 +199,7 @@ class StockAnalyst():
     def get_stock_analyses(
             self,
             ticker
-            ) -> List[str]:
+            ) -> List[Union[HumanMessage, AIMessage, ToolMessage]]:
         """
         Retrieves a list of stock analyses based on a given ticker symbol.
         This function interacts with the state graph to stream events related 
@@ -210,7 +210,7 @@ class StockAnalyst():
         ticker : str
             The stock symbol (ticker) of the company to get suggestions for.
         Returns:
-        List[str]: A list of messages containing stock suggestions.
+        List[Union[HumanMessage, AIMessage, ToolMessage]]: A list of messages of various types.
         """
 
         events = self.graph.stream(
@@ -220,6 +220,7 @@ class StockAnalyst():
             },
             stream_mode='values'
         )
+        # run the events and collect the current (last emitted) messages in a list
         messages = []
         for event in events:
             if 'messages' in event: