UUID

uuid.js

// https://stackoverflow.com/questions/105034/how-to-create-guid-uuid
// https://gist.github.com/jed/982883

function uuid(rng) {
  rng = rng || Math.random.bind(Math)
  function gen(a) {
    return a
      ? (a ^ rng() * 16 >> a/4).toString(16) 
      : ([1e7] + -1e3 + -4e3 + -8e3 + -1e11).replace(/[018]/g, gen)
  }
  return gen()
}