# File lib/bundler/dsl.rb, line 176
    def group(*args, &blk)
      opts = Hash === args.last ? args.pop.dup : {}
      normalize_group_options(opts, args)

      @groups.concat args

      if opts["optional"]
        optional_groups = args - @optional_groups
        @optional_groups.concat optional_groups
      end

      yield
    ensure
      args.each { @groups.pop }
    end