[
    {
        "name": "address",
        "rules": { "nested_object":{
            "street": "required",
            "zip": ["required", "positive_integer"],
            "city": {"one_of": ["Kiev", "Kharkiv"] }
        }}
    },

    {
        "name": "address_with_custom_error",
        "rules": { "nested_object":{
            "street": "required",
            "zip": ["required", "positive_integer"],
            "city": {"one_of": ["Kiev", "Kharkiv"] }
        }},
        "error": "WRONG_ADDRESS"
    }
]