public function initHierarchySync($synckey)
{
$this->_as->state->loadState(array(), $synckey, Horde_ActiveSync::REQUEST_TYPE_FOLDERSYNC);
// Refresh the cache since it might have changed like e.g., if synckey
// was empty.
$this->_cache->loadCacheFromStorage();
return $this->_as->state->getKnownFolders();
}