Isilon / OneFS Rest API Statistics API - complex types def?

The OneFS Rest API is quiet useful given its self documenting nature, however there are some statistic keys which return complex data structures. For example, platform/1/statistics/history?key=node.clientstats.proto.smb2 . If you look at the description of this key you can see that the return type is stats_client_proto_list_v2 which means it is returning a complex type.

Going to the definition of the key only gives us the type:

{
    "keys": [
        {
            "aggregation_type": "custom",
            "base_name": null,
            "default_cache_time": 5,
            "description": "Per client-protocol-class performance statistics for SMB2",
            "key": "node.clientstats.proto.smb2",
            "policies": [
                {
                    "interval": 5,
                    "persistent": false,
                    "retention": 1200
                }
            ],
            "policy_cache_time": 5,
            "real_name": null,
            "scope": "node",
            "type": "stats_client_proto_list_v2",
            "units": "none"
        }
    ]
}

My question is where / how can we find more information on these complex types (not just for this one key, but in general)?

Thank you!