die "unknown version" if $params{version} &&
($params{version} < 0 || $params{version} > $params{dbfile}->backend_data) ;
my $path = $self->_filesystem_path($params{dbfile},$params{version});
die "no file found in backend get_mtime" if !-f $path;
my @st = stat($path);
my $dt = DateTime->from_epoch(epoch => $st[9])->clone();
die "unknown version" if $params{version} &&
($params{version} < 0 || $params{version} > $params{dbfile}->backend_data) ;
my $path = $self->_filesystem_path($params{dbfile},$params{version});
die "no file found in backend get_mtime" if !-f $path;
my @st = stat($path);
my $dt = DateTime->from_epoch(epoch => $st[9])->clone();