Jump to specific page in Gravity Forms multi-page form

functions.php

<?php

// ONLY FOR TESTING
add_filter("gform_pre_render", "gform_skip_page");
function gform_skip_page($form) {
    if(!rgpost("is_submit_{$form['id']}") && rgget('form_page'))
        GFFormDisplay::$submission[$form['id']]["page_number"] = rgget('form_page');
    return $form;
}