<?php
/**
 * @file
 * field_group_multiple.install
 */

/**
 * Implements hook_install().
 */
function field_group_multiple_install() {
  // set module weight higher then this of field_group
  // we want that our module starts after field_group functions
  $field_group_weight = db_select("system", "s")
    ->fields("s", array("weight"))
    ->condition('name', 'field_group')->execute()->fetchField(0);

  $field_group_multiple_weight = $field_group_weight + 1;
  db_update('system')->fields(array('weight' => $field_group_multiple_weight))
    ->condition('name', 'field_group_multiple')
    ->execute();
}