Supports for ValueObject

[fenric]

associated with #3

class Product
{
    public function setWeight(WeightValueObject $weight)
}

class WeightValueObject
{
    public function setWeight(float $weight)
    public function setUnit(WeightUnitEnum $unit)
}

enum WeightUnitEnum
{
    case Kilogram;
}

{
  "product": {
    "weight": {
      "weight": 123.45,
      "unit": "kg"
    }
  }
}