1. headers http header: content-security-policy: prefetch-src

  2. headers http header: sec-fetch-dest

  3. headers http header: sec-fetch-mode

  4. headers http header: sec-fetch-site

  5. headers http header: sec-fetch-user

  6. headers http header: sec-purpose: `sec-purpose` for `<link rel="prefetch">` prefetch

  7. headers http header: sec-purpose: `sec-purpose` for `<script type="speculationrules">` prefetch