如何在到达节点red上的助理节点V2之前提供Watson Assistant上下文变量

[
    {
        "id": "nodeA",
        "type": "watson-assistant",
        "credentials": "your-watson-credentials",
        "assistantId": "your-assistant-id",
        "sessionId": "your-session-id",
        "output": {
            "text": {
                "values": [
                    "Hello! How can I assist you today?"
                ]
            },
            "context": {
                "new_variable": "some_value"
            }
        },
        "x": 150,
        "y": 100,
        "wires": [
            ["nodeV2"]
        ]
    },
    {
        "id": "nodeV2",
        "type": "watson-assistant",
        "credentials": "your-watson-credentials",
        "assistantId": "your-assistant-id",
        "sessionId": "your-session-id",
        "input": {
            "context": {
                "default": "{{payload.context}}"
            }
        },
        "output": {
            "text": {
                "values": [
                    "You previously mentioned: {{payload.context.new_variable}}"
                ]
            }
        },
        "x": 350,
        "y": 100,
        "wires": []
    }
]