Simplify a little RelationRegistry by inheriting from Graph class
Simplify a little RelationRegistry by inheriting from Graph class

kwando/rom,pvcarrera/rom,rom-rb/rom,rom-rb/rom,cored/rom,dekz/rom,pdswan/rom,rom-rb/rom,denyago/rom,pxlpnk/rom,jeremyf/rom,vrish88/rom,endash/rom,Snuff/rom,dcarral/rom