Creating a CAS with a classloader that has no access to org.apache.uima.jcas.cas breaks JCas

[reckart]

Describe the bug
Creating a CAS with a classloader that has no access to org.apache.uima.jcas.cas breaks JCas.

To Reproduce
Steps to reproduce the behavior:

1. Create a CAS using a resource manager that has an extension classloader set which has no access to org.apache.uima.jcas.cas
2. Try creating an annotation in that CAS using CAS.createAnnotation.
3. Exception that TOP cannot be found

Expected behavior
Should work. Actually, I think that well-known UIMA JCas classes should always be loaded through the UIMA frameworks's own classloader (e.g. the classloader for the CAS class) and not through the extension classloader.

Please complete the following information:

• Version: 3.5.0