    # File lib/compass/sass_extensions/sprites/image.rb, line 61
            def repeat
              @repeat ||= begin
                rep = (get_var_file("repeat") || options.get_var("repeat") || Sass::Script::String.new(NO_REPEAT)).value
                unless VALID_REPEATS.include? rep
                  raise SpriteException, "Invalid option for repeat \"#{rep}\" - valid options are #{VALID_REPEATS.join(', ')}"
                end

                rep
              end
            end