Files.GetDirectory returns undefined type(s)

It seems as Files.GetDirectory should return type “List.Item.File” which inherits a “type” from List.Item.Base which should be defined as:

Code:
"type": {
      "enums": [
        "unknown",
        "movie",
        "episode",
        "musicvideo",
        "song",
        "picture",
        "channel"
      ],
      "type": "string",
      "default": "unknown"
    }

but i can easily get enums that are not defined such as type album as below, others are possible as well…

Code:
{
    "files": [
        {
            "file": "musicdb://albums/2/",
            "filetype": "directory",
            "id": 2,
            "label": "Fistful of Metal",
            "size": 0,
            "title": "Fistful of Metal",
            "type": "album",
        }
    ],
    "limits": {
        "end": 1,
        "start": 0,
        "total": 505
    }
}