code: function f (data, opts, callback) {
    data = unpack(data)
  
    if (!callback) {
      [callback, opts] = [opts, {}]
    }
  
    let match = opts.match || /\sx($|\s)/
    let need = []
  
    for (let browser in data.stats) {
      let versions = data.stats[browser]
      for (let version in versions) {
        let support = versions[version]
        if (support.match(match)) {
          need.push(browser + ' ' + version)
        }
      }
    }
  
    callback(need.sort(browsersSort))
  }
docs: Convert Can I Use data