PI 7.0 unable to import class

Hello,

I'm trying to create a UDF to accomplish almost exactly like: how to Extract  characters from a string

We've attributed the issue below being that the "import" of java.util.StringTokenizer, isn't working...

Here's the sample code:

Here's the error message I get:

From what I can tell, our PI system is utilizing Java 1.7, so the class should be there.  Has anyone else run into this issue?  Is there additional configuration that's required?

Regards,

Jose