Even with what one would assume would be the correct way to handle this, it doesn't seem to function.
$identifier(test,test) is fine, but if you wanted to pass a comma in $2-, it treats everything after the comma as $3-.
I propose changing this, so if you put quotations around $2-, it will treat the whole instance as a string and *NOT* $3-.
Therefore:
$identifier(test,"test1, test2") would return:
$1 = test
$2- = test1, test2