code: function hash(password, salt) {
    var iterations = arguments[2] === undefined ? 1024 : arguments[2];
    var keylen = arguments[3] === undefined ? 32 : arguments[3];
    var digest = arguments[4] === undefined ? 'sha256' : arguments[4];
    var encoding = arguments[5] === undefined ? 'hex' : arguments[5];
  
    return (0, _mzCrypto.pbkdf2)(password, salt, iterations, keylen, digest).then(function (buf) {
      return buf.toString(encoding);
    });
  }
docs: Hash a password with salt.
  
  @method
  @param {String} password
  @param {string} salt
  @param {Number} [iterations] 1024
  @param {Number} [keylen] 32
  @param {String} [digest] sha256
  @param {String} [encoding] hex
  @return {Promise} by default 64 of password_hash length.