Hello, I have a question regarding the XenForo_Search_SourceHandler_Abstract class. I want to extend the method "processConstraints". Controllers and Models can be easily extended by creating an event listener like "load_class_controller" or "load_class_model". How I can do this in abstract classes? I found the "search_source_create" event listener but I don't know how to use it and if this the right one for extending the abstract class. Can someone give me a short example how I can extend the XenForo_Search_SourceHandler_Abstract class? Thanks in advanced.