The documentation of setTpbMapping incorrectly states "The path begins with the protocol specification followed by the path to the resource. A special protocol "res:" should be used to specify resource in the classpath."
In reality the "res:" protocol is not supported, and instead of a path to the resource, it is a bundle name.
1. Revise documentation
2. Consider implementing the 'res:' protocol to actually accept a classpath resource.