How to use the prebuild-install/util.getDownloadUrl function in prebuild-install

log.warn('install', 'prebuilt binaries may be out of date!')
} else if (!npm && /node_modules/.test(process.cwd())) {
  // This is a NOOP conditional that is used to handle certain situations where
  // the PM may build from source instead of attempting to download the binary.
} else if (!(typeof pkg._from === 'string')) {
  log.info('install', 'installing standalone, skipping download.')
  process.exit(1)
} else if (pkg._from.length > 4 && pkg._from.substr(0, 4) === 'git+') {
  log.info('install', 'installing from git repository, skipping download.')
  process.exit(1)
} else if (opts.compile === true || opts.prebuild === false) {
  log.info('install', '--build-from-source specified, not attempting download.')
  process.exit(1)
}

prebuildDL(prebuildUtil.getDownloadUrl(opts), opts, function(err) {
  if (err) {
    log.warn('install', err.message);
    process.exit(1);
  }

  log.info('install', 'Successfully installed iltorb binary!');
});