title: How to have more options while using the woocommerce_available_variation hook
body: <p>I using the following WooCommerce hook</p>
  
  <pre class="lang-php prettyprint-override"><code>function dvpi_available_variation( $variations ) {
      echo '&lt;pre class="debug"&gt;', print_r($variations), '&lt;/pre&gt;'; 
      return $variations;
  }
  add_filter( 'woocommerce_available_variation', 'dvpi_available_variation' );
  </code></pre>
  
  <p>This gives me all sorts of details about the variations, but suppose I want to know the (parent) id of the product itself, how do I do this best?</p>