def do_get_block(req, proxy, conn, &block)
    @request_filter.each do |filter|
      filter.filter_request(req)
    end
    if str = @test_loopback_response.shift
      dump_dummy_request_response(req.body.dump, str) if @debug_dev
      conn.push(HTTP::Message.new_response(str))
      return
    end
    content = ''
    res = HTTP::Message.new_response(content)
    @debug_dev << "= Request\n\n" if @debug_dev
    sess = @session_manager.query(req, proxy)
    res.peer_cert = sess.ssl_peer_cert
    @debug_dev << "\n\n= Response\n\n" if @debug_dev
    do_get_header(req, res, sess)
    conn.push(res)
    sess.get_data() do |str|
      block.call(str) if block
      content << str
    end
    @session_manager.keep(sess) unless sess.closed?
    commands = @request_filter.collect { |filter|
      filter.filter_response(req, res)
    }
    if commands.find { |command| command == :retry }
      raise Client::RetryableResponse.new
    end
  end
def do_get_block(req, proxy, conn, &block)
    @request_filter.each do |filter|
      filter.filter_request(req)
    end
    if str = @test_loopback_response.shift
      dump_dummy_request_response(req.body.dump, str) if @debug_dev
      conn.push(HTTP::Message.new_response(str))
      return
    end
    content = ''
    res = HTTP::Message.new_response(content)
    @debug_dev << "= Request\n\n" if @debug_dev
    sess = @session_manager.query(req, proxy)
    res.peer_cert = sess.ssl_peer_cert
    @debug_dev << "\n\n= Response\n\n" if @debug_dev
    do_get_header(req, res, sess)
    conn.push(res)
    sess.get_data() do |str|
      block.call(str) if block
      content << str
    end
    @session_manager.keep(sess) unless sess.closed?
    commands = @request_filter.collect { |filter|
      filter.filter_response(req, res)
    }
    if commands.find { |command| command == :retry }
      raise Client::RetryableResponse.new
    end
  end
!! CAUTION !!
   Method 'do_get*' runs under MT conditon. Be careful to change.