The switch to Java 8 and thus to Collectors.toMap(…) to assemble the root object's methods as functions broke due to the fact that overloaded methods have the same name which causes a collision in keys when preparing the map of functions.
We now use the same approach as before, of letting later methods trump earlier ones as this fixes the original bug. Filed DATACMNS-1026 to keep track of that problem.
Related tickets: DATACMNS-1026.