001_sometest.t
--------------
use_ok( $CLASS );

my $obj = $CLASS->new(
    filename => $logfile,
);
isa_ok( $obj, $CLASS );

ok( -e $logfile, "$CLASS created logfile" );

open my $fh, '>>', $logfile
    or die "Cannot open '$logfile' for appending: $!\n";
my $rc = flock( $fh, LOCK_EX | LOCK_NB );
ok( !$rc, "Cannot flock $logfile" );