# File lib/rbot/core/utils/httputil.rb, line 241
    def setup_headers(hdr)
      hdr['if-modified-since'] = self.date.rfc2822

      debug "ims == #{hdr['if-modified-since']}"

      if etag = self.response['etag']
        hdr['if-none-match'] = etag
        debug "etag: #{etag}"
      end
    end