code: function (binding, subpath, pred) {
      var args = Util.resolveArgs(
        arguments,
        'binding', function (x) { return Util.canRepresentSubpath(x) ? 'subpath' : null; }, '?pred'
      );
  
      return function (event) {
        var value = event.target.value;
        if (!args.pred || args.pred(value)) {
          binding.remove(args.subpath);
        }
      };
    }
docs: Create callback used to delete binding value on an event.
  @param {Binding} binding binding
  @param {String|String[]} [subpath] subpath as a dot-separated string or an array of strings and numbers
  @param {Function} [pred] predicate
  @returns {Function} callback
  @memberOf Callback