code: function (subpath, newValue) {
      var args = Util.resolveArgs(arguments, '?subpath', 'newValue');
      update(this, args.subpath, Util.constantly(args.newValue));
      return this;
    }
docs: Set binding value.
  @param {String|Array} [subpath] subpath as a dot-separated string or an array of strings and numbers
  @param {*} newValue new value
  @return {Binding} this binding