docs: function stringPadStart (str, targetLength, padString, UNDEFINED) {
    var rest = '' + str
    targetLength = targetLength >> 0
    padString = padString === UNDEFINED ? ' ' : '' + padString
    if (rest.padStart) {
      return rest.padStart(targetLength, padString)
    }
    if (targetLength > rest.length) {
      targetLength -= rest.length
      if (targetLength > padString.length) {
        padString += stringRepeat(padString, targetLength / padString.length)
      }
      return padString.slice(0, targetLength) + rest
    }
    return rest
  }