Adding a new object in rsvp

I want to add a new object type in packet-rsvp.c. As i saw i have to add it in enum rsvp_classes according to its C-Num and also add it in value_string rsvp_class_vals[]. I' m not quite sure what should be done with:
rsvp_class_to_filter_num (int classnum) {} should i just add a new filter with the object's name according to its C-Num? and rsvp_class_to_tree_type (int classnum) {} i don't understand the use of tree types "TT_ObjectName", what if i add another TT_ObjectName with a new object in tree types list enum? Should i add it at the end?