public void SetBookmarked(int position, bool mark)
{
if (bookmarkBuffer != null)
{
bookmarkBuffer.SetBookmarked(position, mark);
}
}
public void ToggleBookmark()
{
IBookmarkBuffer markBuffer = GetContent <IBookmarkBuffer> ();
Debug.Assert(markBuffer != null);
int position = markBuffer.CursorPosition;
markBuffer.SetBookmarked(position, !markBuffer.IsBookmarked(position));
}