# File lib/rubigen/lookup.rb, line 62
      def sources
        if read_inheritable_attribute(:sources).blank?
          if superclass == RubiGen::Base
            superclass_sources = superclass.sources
            diff = superclass_sources.inject([]) do |mem, source|
              found = false
              application_sources.each { |app_source| found ||= true if app_source == source}
              mem << source unless found
              mem
            end
            write_inheritable_attribute(:sources, diff)
          end
          active.use_component_sources! if read_inheritable_attribute(:sources).blank?
        end
        read_inheritable_attribute(:sources)
      end