title: Adding values to a multiple select with jQuery's select2
body: <p>I'm using the <a href="http://ivaynberg.github.io/select2/" rel="noreferrer"><code>select2</code></a> jQuery plugin on a <code>&lt;select&gt;</code> with <code>multiple="multiple"</code>. I need to <em>add</em> values to the selected list (i.e. not to all the options, but to the selected options, without adding a new option).</p>
  
  <p>I know I can set the selected options with <a href="http://ivaynberg.github.io/select2/#programmatic" rel="noreferrer">this</a>:</p>
  
  <pre><code>$("#the_select").select2("val", "the_option_value"); 
  </code></pre>
  
  <p>Or, for multiple selections:</p>
  
  <pre><code>$("#the_select").select2("val", ["an_option_value","another_option_value"]); 
  </code></pre>
  
  <p>However, is there a way I can add <em>selected options</em> to the list (i.e. make an option selected) without removing the others?</p>