lib/types/index.js
function uuid(options, buffer, offset) {
  let uuid;
  if (options) {
    if (util.isArray(options.random)) {
      uuid = new Uuid(utils.allocBufferFromArray(options.random));
    }
  }
  if (!uuid) {
    uuid = Uuid.random();
  }
  if (buffer instanceof Buffer) {
    //copy the values into the buffer
    uuid.getBuffer().copy(buffer, offset || 0);
    return buffer;
  }
  return uuid.toString();
}
function uuid(options, buffer, offset) {
  let uuid;
  if (options) {
    if (util.isArray(options.random)) {
      uuid = new Uuid(utils.allocBufferFromArray(options.random));
    }
  }
  if (!uuid) {
    uuid = Uuid.random();
  }
  if (buffer instanceof Buffer) {
    //copy the values into the buffer
    uuid.getBuffer().copy(buffer, offset || 0);
    return buffer;
  }
  return uuid.toString();
}
<p><strong>Backward compatibility only, use [Uuid]{@link module:types~Uuid} class instead</strong>.</p>
Generate and return a RFC4122 v4 UUID in a string representation.
@deprecated Use [Uuid]{@link module:types~Uuid} class instead