{
    "_id" : "test1",
    "title" : "test1",
    "description" : "Adam's Api Root",
    "versions" : [
        "version 1",
        "version 2"
    ],
    "max_content_length" : 50000
}

ApiRootDocument apiRoot = apiRootsRepository.findById(id);

{
    "title": "test1",
    "description": "Adam's Api Root",
    "versions": [
        "version 1",
        "version 2"
    ],
    "max_content_length": 0
}

@Expose
@SerializedName("max_content_length")
private int maxContentLength;