private function substituteTokens(array $tokens)
{
$result = array();
foreach ($tokens as $token) {
$temp = (array) $token;
$temp = $temp[0];
if (isset(self::$substituteTokens[$temp])) {
foreach (self::$substituteTokens[$temp] as $token) {
$result[] = $token;
}
} else {
$result[] = $token;
}
}
return $result;
}