<services>
  <service name="download_url">
    <param name="protocol">http</param>
    <param name="host">ftp.gnu.org</param>
    <param name="path">/gnu/m4/m4-1.4.16.tar.bz2</param>
  </service>
  <service name="verify_file">
    <param name="file">_service:download_url:m4-1.4.16.tar.bz2</param>
    <param name="verifier">sha256</param>
    <param name="checksum">42500c1fddd90bcb161e6b58de931d769929c495c124112d67428a23543db90c</param>
  </service>
</services>