Recommended alternative to mutable __proto__ from mozilla

protobull.js

Object.create2 = function(a, b) {
  var res = Object.create(a);
  for (var x in b) { if (b.hasOwnProperty(x)) res[x] = b[x]; }
  return res;
}

var o = Object.create2(foo, { f:0, g:1, ... });