text: // The other three classes will extend `Employee`. 
  // In addition to `Employee`'s properties and methods, `Engineer` will also have:
  
  //   * github  // GitHub username
  
  //   * getGithub()
  
  //   * getRole() // Overridden to return 'Engineer'
  
  //require class_employee file for class Employee to be extended
  const Employee = require("./class_employee");
  
  class Engineer extends Employee {
  
      //add github parameter, which will refers to GitHub username in the property
      //since the Engineer constructor should also have the Employee's properties and methods, include those as parameters in addition to github
      constructor (name, id, email, github) {
  
          //add super as a requirement for the extended class, which contains the Employee parameters
          super(name, id, email);
  
          //set property specific to Engineer class
          this.github = github;
      }
  
      //set two methods, one of which changes the getRole() from the Employee class 
      getGithub() {
          return this.github;
      }
  
      getRole() {
          return "Engineer";
      }
  
  }
  
  
  //export engineer so it can be used externally
  module.exports = Engineer;