Class cast exception with jdk.internal.loader.ClassLoaders$AppClassLoader #54

I am doing new org.xmlresolver.XMLResolverConfiguration() in xmlresolver v3.0.2; eventually, it gets to this line in XMLResolverConfiguration:
for (URL url : ((URLClassLoader) XMLResolverConfiguration.class.getClassLoader())...)...,
which assumes that the class-loader can be cast to URLClassLoader, but in my case it is jdk.internal.loader.ClassLoaders$AppClassLoader, so I get ClassCastException...

Please advise :)