old_contents: from c3nav.mapdata.models import Level, Package, Source
  from c3nav.mapdata.models.geometry import Area, Building, Obstacle
  
  ordered_models = (Package, Level, Source, Building, Area, Obstacle)
  
new_contents: from c3nav.mapdata.models import Level, Package, Source
  from c3nav.mapdata.models.geometry import Area, Building, Door, Obstacle
  
  ordered_models = (Package, Level, Source, Building, Area, Door, Obstacle)
  
subject: add Doors to packageio