    # File lib/rubygems.rb, line 488
      def self.path
        @gem_path ||= nil

        unless @gem_path then
          paths = if ENV['GEM_PATH'] then
                    [ENV['GEM_PATH']]
                  else
                    [default_path]
                  end

          if defined?(APPLE_GEM_HOME) and not ENV['GEM_PATH'] then
            paths << APPLE_GEM_HOME
          end

          set_paths paths.compact.join(File::PATH_SEPARATOR)
        end

        @gem_path
      end