dependency_injection_refactor1_example.java

class Laptop{}

/* Added video interface */
interface VideoCable{ 
  public void connect(Laptop device); 
}

class DisplayPortCable implements VideoCable{
  public void connect(Laptop device){
    connectedDevice = device;
  }

  private Laptop connectedDevice; 
}

class Monitor{
  public Monitor(VideoCable videoConnector){
     this.videoConnector = videoConnector;
  }

  public void connectToDevice(Laptop device){
    videoConnector.connect(device);
  }

  private VideoCable videoConnector; 
}