[BUG] nodejs-express-server Controller.js response.end() not found

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used? 4.3.1
• Have you search for related issues/PRs?
• What's the actual output vs expected output?

Description

nodejs-express-server generator generates code that doesn't work well.
Specifically it produces Controller.js with calls to response.end() while it doesn't seem to be defined.
E.g.:

  static sendError(response, error) {
    response.status(error.code || 500);
    if (error.error instanceof Object) {
      response.json(error.error);
    } else {
      response.end(error.error || error.message);
    }
  }

Here the call to response.end() raises Method not allowed error on the front-end instead not the actual error whatever it was.

Here is a part of my package.json:

{
  "dependencies": {
    "body-parser": "^1.19.0",
    "camelcase": "^5.3.1",
    "cookie-parser": "^1.4.4",
    "cors": "^2.8.5",
    "express": "^4.16.4",
    "express-openapi-validator": "^3.9.1",
    "js-yaml": "^3.13.1",
    "lodash": "^4.17.15",
    "nodemon": "^2.0.4",
    "ono": "^5.0.1",
    "openapi-sampler": "^1.0.0-beta.15",
    "swagger-ui-express": "^4.0.2",
    "winston": "^3.2.1"
  },
  "devDependencies": {
    "axios": "^0.19.0",
    "chai": "^4.2.0",
    "chai-as-promised": "^7.1.1",
    "eslint": "^5.16.0",
    "eslint-config-airbnb-base": "^14.0.0",
    "eslint-plugin-import": "^2.17.2",
    "mocha": "^7.1.1"
  },
}

openapi-generator version

4.3.1

Start by examining the generated Controller.js, especially the sendError method and its response.end() call. Reproduce the issue with the nodejs-express-server generator using the reported OpenAPI Generator 4.3.1 setup. Done means the generated error response returns the actual error instead of raising a method-not-allowed error.