title: public void add(int a, int... b) {
body: <p>Could someone show me a practical a use of the ... array method delcaration?
  Is it just a way to declare an optional parameter instead of passing null value?</p>
  
  <pre><code>public void add(int a, int... b) {
   // do something
  }
  
  add(1);
  add(1,2,3); 
  </code></pre>