function _randomChars(howMany) {
  let
    value = [],
    rnd = null;

  // make sure that we do not fail because we ran out of entropy
  try {
    rnd = crypto.randomBytes(howMany);
  } catch (e) {
    rnd = crypto.pseudoRandomBytes(howMany);
  }

  for (var i = 0; i < howMany; i++) {
    value.push(RANDOM_CHARS[rnd[i] % RANDOM_CHARS.length]);
  }

  return value.join('');
}
Random name generator based on crypto.
Adapted from http://blog.tompawlak.org/how-to-generate-random-values-nodejs-javascript

@param {number} howMany
@returns {string} the generated random name
@private