Is there an equivalent field to Label/Publisher in taglib-sharp?

I'm trying to update the label/publisher field using Taglib-sharp, but I can't see it anywhere in its Object Hierarchy using Object Browser.

I've searched through google and the documentation and it looks like it's a field that's not catered for.

Before I look for alternatives (can any one suggest any?) that can edit those field, I thought I'd have one last crack and ask within the StackOverflow community who is familiar with TagLib-sharp that had a more informed opinion?

Thanks in Advance,

Francis

Update : I've investigated other libraries such as mpg123 & UltraID3Lib but they seem to have the same limitations.

Solution

Well, Daniel Fuchs answer didn't work for me. But, it was a beginning.

The step by step to add a field in the TagLib-sharp code is:

Download Source
Open the File TagLib/Tag.cs and insert the following code (I inserted it below PerformersSort, line 250):
```
public virtual string Publisher
{
    get { return ""; }
    set { }
}
```

Open the File TagLib/Id3v2/Tag.cs and insert the following code (I inserted it below PerformersSort, line 1292):

public override string Publisher
{
    get { return GetTextAsString(FrameType.TPUB); }
    set { SetTextFrame(FrameType.TPUB, value); }
}

Open the File TagLib/Id3v2/FrameTypes.cs and insert the following code (I inserted it below TPOS, line 71):
```
public static readonly ReadOnlyByteVector TPUB = "TPUB";
```

Now comes the "Aha" thing. Open the File TagLib/CombinedTag.cs and insert the following code (I inserted it below PerformersSort, line 318):

public override string Publisher
{
    get
    {
        foreach (Tag tag in tags)
        {
            if (tag == null)
                continue;

            string value = tag.Publisher;

            if (value != null)
                return value;
        }

        return null;
    }

    set
    {
        foreach (Tag tag in tags)
            if (tag != null)
                tag.Publisher = value;
    }
}

Finally, compile the code.

IMPORTANT: I had problems compiling the code, as well. You must download the SharpZipLib dll (.NET 2.0) and include this dll in the taglib project. Also, I needed to install NUnit, which I made with Nuget. At last, I commented the GDK lib and all its errors inside the test code, since in production it won't be used.