public void Visit(Potion item)
 {
     Console.WriteLine($"\n{nameof(Potion)} received an upgrade!");
     item.Magic += 10;
 }
 public void Visit(Potion item)
 {
     Console.WriteLine($"\n{nameof(Potion)}");
     Console.WriteLine($"- {item.Magic} points of {nameof(Potion.Magic)}");
 }
 public void Visit(Potion item)
 {
     Console.WriteLine($"\n{nameof(Potion)} suffered a downgrade!");
     item.Magic -= 5;
 }