text: // "software entities should be open for extension, but closed for modification."
  
  // Good 👍
  /* interface Vehicle {
    // Tell, Don't Ask Principle
    move(): number
  } */
  
  class Truck {
    move() {
      return 1
    }
  }
  
  class Plane {
    move() {
      return 2
    }
  }
  
  export class MovementCalculator {
    calculate(vehicles) {
      return vehicles.reduce((previous, current) => previous + current.move(), 0)
    }
  }
  