function merge (varArgs) {
  const args = [].slice.call(arguments)
  const newObj = Object.create(null)
  let id = 0; let key

  while (args[id]) {
    for (key in args[id]) {
      newObj[key] = args[id][key]
    }

    id++
  }

  return newObj
}
Merge several objects. Properties from earlier objects are overwritten by
laters's in case of conflict.

@param {...Object.<string, string>} var_args One or more objects of strings.
@return {!Object.<string, string>} An object of strings.