id-unique-generator.js

var ID = function () {
  // Math.random should be unique because of its seeding algorithm.
  // Convert it to base 36 (numbers + letters), and grab the first 9 characters
  // after the decimal.
  const start = Math.random().toString(36).substr(2, 2);
  const end = Math.random().toString(36).substr(2, 2);
  return '_' + start + end;
};