public function associateRouteTable($routeTableId, $subnetId)
{
$result = null;
$options = array('RouteTableId' => (string) $routeTableId, 'SubnetId' => (string) $subnetId);
$action = ucfirst(__FUNCTION__);
$response = $this->client->call($action, $options);
if ($response->getError() === false) {
$sxml = simplexml_load_string($response->getRawContent());
$result = (string) $sxml->associationId;
}
return $result;
}