    # File lib/stella.rb, line 178
        def canonical_uri(uri)
          return nil if uri.nil?
          if uri.kind_of?(URI)
            uri = Addressable::URI.parse uri.to_s
          elsif uri.kind_of?(String)
            uri &&= uri.to_s
            uri.strip! unless uri.frozen?
            uri = "http://#{uri}" unless uri.match(/^https?:\/\//)
            uri = Addressable::URI.parse(uri)
          end
          uri.scheme ||= 'http'
          uri.path = '/' if uri.path.to_s.empty?
          uri
        end