on_chat_model_stream event chunk content in astream_events() is list not str

[Maxew42]

When using astream_events() with ChatBedrockConverse, the on_chat_model_stream events do not have the format I was expecting. The field data.chunk.content is a list rather then a string.
This is not aligned with the behaviour presented here for chat models. This is also not aligned with the behaviour of the ChatBedrock model, which gives a string. Its also not aligned with the behaviour of ChatBedrockConverse described in the table below here.

Is this intentional ?

Code:

from langchain_aws import ChatBedrockConverse
import os

async def chat_langchain_astream_events():
    llm = ChatBedrockConverse(
        model="anthropic.claude-3-5-sonnet-20240620-v1:0",
        region_name="eu-central-1",
        aws_access_key_id=os.environ["AWS_ACCESS_KEY_ID"],
        aws_secret_access_key=os.environ["AWS_SECRET_ACCESS_KEY"],
        )

    message = [("user", "Hey, how are you?")]
    events = []
    async for event in llm.astream_events(message, version="v2"):
        events.append(event)
    print(events[1:3])

Output:

[{'event': 'on_chat_model_stream', 'run_id': '6915e633-7473-42d0-bbab-b894920929c8', 'name': 'ChatBedrockConverse', 'tags': [], 'metadata': {'ls_provider': 'amazon_bedrock', 'ls_model_name': 'anthropic.claude-3-5-sonnet-20240620-v1:0', 'ls_model_type': 'chat', 'ls_temperature': None}, 'data': {'chunk': AIMessageChunk(content=[], additional_kwargs={}, response_metadata={}, id='run--6915e633-7473-42d0-bbab-b894920929c8')}, 'parent_ids': []}, 
 {'event': 'on_chat_model_stream', 'run_id': '6915e633-7473-42d0-bbab-b894920929c8', 'name': 'ChatBedrockConverse', 'tags': [], 'metadata': {'ls_provider': 'amazon_bedrock', 'ls_model_name': 'anthropic.claude-3-5-sonnet-20240620-v1:0', 'ls_model_type': 'chat', 'ls_temperature': None}, 'data': {'chunk': AIMessageChunk(content=[{'type': 'text', 'text': 'Hello', 'index': 0}], additional_kwargs={}, response_metadata={}, id='run--6915e633-7473-42d0-bbab-b894920929c8')}, 'parent_ids': []}]

in particular ...'data': {'chunk': AIMessageChunk(content=[{'type': 'text', 'text': 'Hello', 'index': 0}], ...
Where I would expect ...'data': {'chunk': AIMessageChunk(content='Hello', ... as