$build_id_from_cache_first_ajax = $this->getFormBuildId();
$this->assertNotEquals($build_id_from_cache_initial, $build_id_from_cache_first_ajax, 'Build id is changed in the simpletest-DOM on first AJAX submission');
$build_id_from_cache_first_ajax = $this->getFormBuildId();
$this->assertNotEquals($build_id_from_cache_initial, $build_id_from_cache_first_ajax, 'Build id is changed in the simpletest-DOM on first AJAX submission');