How multiple UDTs are run?

[asdf]

I have two UDTs, both have only one line: require("path/to/file.php"); Then, I have a common library I require_once in both of file.php. Everything is fine when I call only one UDT. But, if both UDTs are on the same page, the variable set in the common library is unavailable in the latter UDT. In a way this makes sense because it's being required once, but when the same PHP code is run outside CMSMS the variable is available as expected. Then, to confuse me more, a function declared in the same common library is available for the latter UDT.

So, my question is, how UDT is run, is it somehow run in its own session or why variable is not visible but function is?

I'm using 1.9.3 on Ubuntu Linux.