A DESCRIPTION OF THE REQUEST :
The method getControllerMethods() should also add methods of interfaces if they have a default implementation.

JUSTIFICATION :
If the controller class implements an interface with methods that have a default implementation they are not available within the accessible members.
If the controller though implements an interface that has an initialize method that has a default implementation this method will never be called by the FXMLLoader.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
FXMLLoader should consider for initialization also default methods of interfaces.
ACTUAL -
FXMLLoader does not consider default implemented methods coming from interfaces.

CUSTOMER SUBMITTED WORKAROUND :
Define the initialize methods only in superclasses.