Solution Review: Implement an Interface

// Addition interface
interface Addition {
  
  int add(int num1, int num2);
  
}
// Calculator Class Implementing the Addition Interface
class Calculator implements Addition {
  
  // Overriding the add method of Addition interface
  public int add(int num1, int num2) {
    return num1 + num2;
  }
  
}
class Demo {
  
 public static void main(String args[]) {
   Calculator cal = new Calculator();
   System.out.println(cal.add(10, 20));
 }
  
}