package Ġpl . pol sl . timetable . synchron ization Ċ import Ġpl . pol sl . timetable . synchron ization . sc raper . Category Ċ Ċ interface ĠCategory Clean ing Service Ġ{ ĊĠĠĠ Ġfun Ġremove Non existent Categories ( root Category : ĠCategory ) Ċ }