# File lib/thin/request.rb, line 109
    def persistent?
      # Clients and servers SHOULD NOT assume that a persistent connection
      # is maintained for HTTP versions less than 1.1 unless it is explicitly
      # signaled. (http://www.w3.org/Protocols/rfc2616/rfc2616-sec8.html)
      if @env[HTTP_VERSION] == HTTP_1_0
        @env[CONNECTION] =~ KEEP_ALIVE_REGEXP

      # HTTP/1.1 client intends to maintain a persistent connection unless
      # a Connection header including the connection-token "close" was sent
      # in the request
      else
        @env[CONNECTION].nil? || @env[CONNECTION] !~ CLOSE_REGEXP
      end
    end