title: Method overriding in Angular2
body: <p>I have two components, one is parent and the other is child. Child extends from Parent. Parent has a method open(). Child overloads open() by rewriting and adding a parameter. It results in an error: open() is a property, and the property types do not match across classes.</p>
  
  <pre><code>open() =&gt; void 
  </code></pre>
  
  <p>is not equal to </p>
  
  <pre><code>open(message: string) =&gt; void
  </code></pre>
  
  <p>Parent :</p>
  
  <pre><code>export class ParentClass {
      constructor() { super(); }
  
      open(){
          return "Hello World!";
      }
  }
  </code></pre>
  
  <p>Child:</p>
  
  <pre><code>export class ChildClass extends ParentClass {
      constructor() { super(); }
  
      open(message: string){
          return message;
      }
  }
  </code></pre>