How to clean state in agent?

[axiangcoding]

I have the following state definition:

import operator

class AgentState(TypedDict):
    single_qa_results: Annotated[list[str], operator.add]

I used the operator.add annotation to enable parallel addition of single_qa_result entries. For example:

def single_document_worker(
    state: AgentState,
    config: RunnableConfig,
    writer: StreamWriter,
):
    return {
        "single_qa_results": ["worker results here"],
    }

However, at a certain node, I want to clear the entire single_qa_results list to start a new workflow. For example:

def start_new_workflow(
    state: AgentState,
    config: RunnableConfig,
    writer: StreamWriter,
):
    return {
        "single_qa_results": ???,
    }

How can I achieve this?