def try_open(server)
      options = @options.merge(server.options) # merge connection and server options
      options[:tunnel] ? try_open_tunnel(server, options) : try_open_direct(server, options)
    end
def try_open(server)
      options = @options.merge(server.options) # merge connection and server options
      options[:tunnel] ? try_open_tunnel(server, options) : try_open_direct(server, options)
    end
setup options and call appropriate connection open()