Support of record fields default values

[SokolovAlexanderV]

Hello.
In Avro schemas record fields may have a default value. Using it we can skip some field in JSON file and it still will be valid.

Schema

{
    "type": "record",
    "name": "User",
    "fields": [
        {
            "name": "name",
            "type": "string"
        },
        {
            "name": "age",
            "type": ["null", "int"],
            "default": null
        }
    ]
}

Data

{
    "name": "John"
}

Data is valid though "age" is not provided because schema defines default value for "age".

I have a code to suggest for enabling support of record fields default values.