title: WooCommerce Multi Select for Single Product Field
body: <p>I am trying to add the list box on the single product page, I was wondering no option for multiselect in woocommerce, For <code>get_option</code> fields woocommerce supporting multiselect but for <code>post_meta</code> woocommerce support only single select, Not sure is there any limitation in woocommerce or i could miss something to get multiselect? Here is the below code i tried</p>
  
  <pre><code> function create_multiselect() { 
  
      woocommerce_wp_select(array(
                  'id' =&gt; 'newoptions',
                  'class' =&gt; 'newoptions',
                  'label' =&gt; __('Testing Multiple Select', 'woocommerce'),
                  'options' =&gt; array(
                      '1' =&gt; 'User1',
                      '2' =&gt; 'User2',
                      '3' =&gt; 'User3',
                  ))
              );
  
      }
  
      add_action("woocommerce_product_options_pricing","create_multiselect");
  </code></pre>
  
  <p>Any Suggestion would be great.</p>