public file get_file(long file_id)
{
file res = this.files.FirstOrDefault(f => f.id == file_id);
if (res != null)
{
return(res);
}
foreach (folder f in folders)
{
res = f.get_file(file_id);
if (res != null)
{
return(res);
}
}
return(null);
}
public file add_file(file f)
{
this.files.Add(f); return(f);
}