Multiple classes in one library

[eluser]rvent[/eluser]
Hello,

I am creating a series of web applications and i was thinking to separate each app into its own library. But i wanted to know if it was possible to have more than 1 class defined in each library for example:

Code:

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class Testcenter
{
   function one
   {
   }
}

class Test extends Testcenter
{
   funtion addTest()
   {
   }
}
?>

and so on...?

Thanks