purge_feed_cache (Raggle::Engine)

    # File raggle, line 4955
        def Engine::purge_feed_cache
          urls = {}
          $config['feeds'].each { |feed| urls[feed['url']] = true }
          PStore::new($config['feed_cache_path']) { |cache|
            cache.roots.each { |root|
              unless urls[root]
                $stderr.puts "Purging \"#{root}\"" if $config['verbose']
                cache[root] = nil
              end
            }
          }
        end