content: public class Invoker {
      private Command turnOn1;
      private Command turnOff1;
      private Command turnOn2;
      private Command turnOff2;
      private Command changeChannelFoward;
      private Command changeChannelBackward;
      private Command stereoVolumeUp;
      private Command stereoVolumeDown;
  
      public Invoker(Command turnOn1,
                     Command turnOff1,
                     Command turnOn2,
                     Command turnOff2,
                     Command changeChannelFoward,
                     Command changeChannelBackward,
                     Command stereoVolumeUp,
                     Command stereoVolumeDown){
          this.turnOn1 = turnOn1;
          this.turnOff1 = turnOff1;
          this.turnOn2 = turnOn2;
          this.turnOff2 = turnOff2;
          this.changeChannelFoward = changeChannelFoward;
          this.changeChannelBackward = changeChannelBackward;
          this.stereoVolumeUp = stereoVolumeUp;
          this.stereoVolumeDown = stereoVolumeDown;
      }
      public void pressOn1(){
          this.turnOn1.execute();
      }
      public void pressOff1(){
          this.turnOff1.execute();
      }
      public void pressOn2(){
          this.turnOn2.execute();
      }
      public void pressOff2(){
          this.turnOff2.execute();
      }
      public void pressChannelForward(){
          this.changeChannelFoward.execute();
      }
      public void pressChannelBackward(){
          this.changeChannelBackward.execute();
      }
      public void pressStereoVolumeUp(){
          this.stereoVolumeUp.execute();
      }
      public void pressStereoVolumeDown(){
          this.stereoVolumeDown.execute();
      }
  }
  