spring-data-rest: RepositoryRestMvcConfiguration can no longer be subclassed

Despite the class documentation states that “To customize how the exporter works, subclass this and override…”, that that is no longer possible. The restHandlerMapping() method returns a DelegatingHandlerMapping which has been made package private in commit d7f36b118060157e208aa044eb5c1c038b2c1dc2 related to DATAREST-1540. When subclassing RepositoryRestMvcConfiguration for customisation, I now get the following exception:

Caused by: java.lang.IllegalAccessError: failed to access class org.springframework.data.rest.webmvc.config.DelegatingHandlerMapping from class au.com.onyxtech.horus.config.RepositoryRestConfig$ExtendedRepositoryRestMvcConfiguration$$EnhancerBySpringCGLIB$$186fd9d8 (org.springframework.data.rest.webmvc.config.DelegatingHandlerMapping and au.com.onyxtech.horus.config.RepositoryRestConfig$ExtendedRepositoryRestMvcConfiguration$$EnhancerBySpringCGLIB$$186fd9d8 are in unnamed module of loader 'app')
	at au.com.onyxtech.horus.config.RepositoryRestConfig$ExtendedRepositoryRestMvcConfiguration$$EnhancerBySpringCGLIB$$186fd9d8.restHandlerMapping(<generated>)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
	... 89 common frames omitted