private void AddNewAuthor(object sender, BookRelatedEventArgs e)
{
if (!LibraryDataIO.Instance.Authors.Any(author => author.FullName == e.Author.FullName))
{
LibraryDataIO.Instance.AddAuthor(e.Author);
authorForm?.Close();
adminForm.RefreshAuthors();
}
else
{
MessageBox.Show("Author already exists!");
}
}