function randomString() {
  function s4() {
    return Math.floor((1 + Math.random()) * 0x10000).toString(16).substring(1);
  }

  return s4() + s4() + s4() + s4();
}
Generates a random hex string. Used as namespace for Handsontable instance events.

@return {String} Returns 16-long character random string (eq. `'92b1bfc74ec4'`).