golang json递归数据模型的序列化/反序列化

Lets say I have:

type IObject interface {
}

type Item struct {
    Description string
    Data        []byte
}

type FunctionX1 struct {
    Object IInclusionObject
}

type FunctionX2 struct {
    Object1 IInclusionObject
    Object2 IInclusionObject
}

ItemFunctionX1FunctionX2IObject

FunctionX1{Item{"foo", []byte("bar")}}

"object": {
    "Description": "foo"
    "Data": ...
}

but rather:

"FunctionX1": {
    "item": { 
        "Description": "foo"
        "Data": ...
    }
}

Do I need to do my own JSON marshaller - it does not seem that I can use the existing one.

Related questions in case I need my own. Is there JSON prettifier where I can stream valid but randomly formatted JSON and it to output pretty version (note the JSON could be significantly large - I do not want to generate, parse generate formatted).