class Xcodeproj::Project::Object::FileReferencesFactory

def new_reference(group, path, source_tree)
  ref = case File.extname(path).downcase
        when '.xcdatamodeld'
          new_xcdatamodeld(group, path, source_tree)
        when '.xcodeproj'
          new_subproject(group, path, source_tree)
        else
          new_file_reference(group, path, source_tree)
        end
  configure_defaults_for_file_reference(ref)
  ref
end