langchain/memory/chat_message_histories/dynamodb.py/DynamoDBChatMessageHistory/__init__
class DynamoDBChatMessageHistory:    def __init__(self, table_name: str, session_id: str):
        import boto3

        client = boto3.resource("dynamodb")
        self.table = client.Table(table_name)
        self.session_id = session_id