Mine

      $form['filters'] = array(
        '#type' => 'checkboxes',
      );
      if ($form_values['entity'] == STATES_ADMIN_ENTITY_NODE) {
        $form['filters']['#title'] = t('Permitted node types');
        $form['filters']['#description'] = t('The state machine is only valid for the checked node types.');
        $form['filters']['#options'] = node_get_types('names');
        if (isset($machine) && isset($machine['#types'])) {          
          $form['filters']['#default_value'] = $machine['#types'];
        }
      }