MalforumedURIExceptin when import STG as resource stream in jar

This is for java.
I have a common TTML.stg that I `import "TTML.stg"` in a TTMLClock.stg and a TTMLSmpte.stg

They are all in the same directory.

When I
```
return new STGroupString(Resources.toString(CaptionTemplates.class.getResource(format("templates/%s.stg", name)), StandardCharsets.UTF_8));
```
I get a MalformedURLException always with `null/` as the root directory

Is this a known limitation that import does not work with a stream?

The workaround is to use imporTemplates, which is fine, but without stream support, The `import "Foo.stg"` scheme couldn't work for resources inside jars. I saw a similar bug, but I didn't feel like it fully explained the consequences for Java.