Extension classpath of soapui java integration

I have seen solutions to extending the soapui classpath to custom locations using ClasspathHacker in the soapui library.

However this have always been implemented in the scripts where the imports are made. I wonder if this could be done in java code directly. For example I am constructing a MockRunner in java using the soapui library. In turn this MockRunner takes in a soapui project and extracts the mockservice and runs it. The mockservice operation contains a groovyscript which requires some external library imports. 

Now instead of defining the ClasspathHacker in the groovyscript, can I somehow do this inside the java code, attached to the operation, mockservice or project?