public virtual NSString AddFileWrapper(NSFileWrapper doc)
{
NSString key;
GSFileWrapperDirectoryTypeCheck();
key = doc.PreferredFilename();
if (key == null || key.IsEqualToString(""))
{
NSException.Raise("NSInvalidArgumentException", "Adding file wrapper with no preferred filename.");
return null;
}
if (((NSDictionary)_wrapperData).ObjectForKey(key) != null)
{
// FIXME - handle duplicate names
}
((NSDictionary)_wrapperData).SetObjectForKey(doc, key);
return key;
}