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