MBeanServer.createMBean methods that take a classloader don't work

The MBeanServer.createMBean methods that take an "ObjectName loaderName" argument are completely broken in EAP 6.

These methods call findDelegate to make sure there is already an existing MBean registered with the given name passed in for the new MBean, or else it throws an exception.
This is obviously wrong, as there'd be no point in calling createMBean if it already existed.

javax.management.InstanceNotFoundException: test:service=Test
at org.jboss.as.jmx.PluggableMBeanServerImpl.findDelegate(PluggableMBeanServerImpl.java:1083)
at org.jboss.as.jmx.PluggableMBeanServerImpl.createMBean(PluggableMBeanServerImpl.java:253)