[ERR_HTTP_HEADERS_SENT]: Cannot remove headers after they are sent to the client

我使用的是node.js + Marko.js，偶尔会遇到如下问题：

node:_http_outgoing:771
    throw new ERR_HTTP_HEADERS_SENT('remove');
    ^

Error [ERR_HTTP_HEADERS_SENT]: Cannot remove headers after they are sent to the client
    at __node_internal_captureLargerStackTrace (node:internal/errors:491:5)
    at new NodeError (node:internal/errors:400:5)
    at ServerResponse.removeHeader (node:_http_outgoing:771:11)
    at write (/home/xd/work/coding/nodejs/StockResearchApp/node_modules/finalhandler/index.js:282:9)
    at AsyncResource.runInAsyncScope (node:async_hooks:204:9)
    at listener (/home/xd/work/coding/nodejs/StockResearchApp/node_modules/on-finished/index.js:170:15)
    at onFinish (/home/xd/work/coding/nodejs/StockResearchApp/node_modules/on-finished/index.js:101:5)
    at callback (/home/xd/work/coding/nodejs/StockResearchApp/node_modules/ee-first/index.js:55:10)
    at IncomingMessage.onevent (/home/xd/work/coding/nodejs/StockResearchApp/node_modules/ee-first/index.js:93:5)
    at IncomingMessage.emit (node:events:513:28)
    at endReadableNT (node:internal/streams/readable:1359:12)
    at process.processTicksAndRejections (node:internal/process/task_queues:82:21) {
  code: 'ERR_HTTP_HEADERS_SENT'
}

Node.js v18.13.0
Error: socket hang up
    at connResetException (node:internal/errors:718:14)
    at Socket.socketOnEnd (node:_http_client:520:23)
    at Socket.emit (node:events:525:35)
    at endReadableNT (node:internal/streams/readable:1359:12)
    at process.processTicksAndRejections (node:internal/process/task_queues:82:21) {
  code: 'ECONNRESET'
}

经过排查，发现经常实际上是语法错误，比如把 this.state.x 和 state.x 混用，这两种使用方式有不同的使用场景，要明确区分，不能混用。