code: function Mnemonic(options) {
    if (!(this instanceof Mnemonic))
      return new Mnemonic(options);
  
    this.bits = common.MIN_ENTROPY;
    this.language = 'english';
    this.entropy = null;
    this.phrase = null;
    this.passphrase = '';
  
    if (options)
      this.fromOptions(options);
  }
docs: HD Mnemonic
  @alias module:hd.Mnemonic
  @constructor
  @param {Object} options
  @param {Number?} options.bit - Bits of entropy (Must
  be a multiple of 8) (default=128).
  @param {Buffer?} options.entropy - Entropy bytes. Will
  be generated with `options.bits` bits of entropy
  if not present.
  @param {String?} options.phrase - Mnemonic phrase (will
  be generated if not present).
  @param {String?} options.passphrase - Optional salt for
  key stretching (empty string if not present).
  @param {String?} options.language - Language.