# File lib/net/http/persistent.rb, line 695
  def proxy= proxy
    @proxy_uri = case proxy
                 when :ENV      then proxy_from_env
                 when URI::HTTP then proxy
                 when nil       then # ignore
                 else raise ArgumentError, 'proxy must be :ENV or a URI::HTTP'
                 end

    if @proxy_uri then
      @proxy_args = [
        @proxy_uri.host,
        @proxy_uri.port,
        @proxy_uri.user,
        @proxy_uri.password,
      ]

      @proxy_connection_id = [nil, *@proxy_args].join ':'
    end

    reconnect
    reconnect_ssl
  end