是否可以在处理之前更改mountebank中的请求正文？如果是，我们如何做到这一点呢？

POST /imposters
{
  "port": 8000,
  "protocol": "http",
  "stubs": []
}

POST /imposters/8000/stubs
{
  "predicates": [
    {
      "equals": {
        "path": "/api/endpoint"
      }
    }
  ],
  "responses": [
    {
      "is": {
        "statusCode": 200,
        "headers": {
          "Content-Type": "application/json"
        },
        "body": {
          "message": "Hello, World!"
        }
      }
    }
  ]
}

POST /imposters/8000/stubs
{
  "predicates": [
    {
      "equals": {
        "path": "/api/endpoint"
      }
    }
  ],
  "responses": [
    {
      "is": {
        "statusCode": 200,
        "headers": {
          "Content-Type": "application/json"
        },
        "body": {
          "message": "Hello, World!"
        }
      },
      "decorate": {
        "mode": "replace",
        "key": "request.body",
        "template": {
          "newKey": "newValue"
        }
      }
    }
  ]
}