# File lib/sup/buffer.rb, line 350
  def spawn_unless_exists title, opts={}
    new = 
      if @name_map.member? title
        raise_to_front @name_map[title] unless opts[:hidden]
        false
      else
        mode = yield
        spawn title, mode, opts
        true
      end
    [@name_map[title], new]
  end