my $guard = $schema->txn_scope_guard;

my $rs = $schema->resultset('TestTable')->search({
    status => 'available'
},
{ 
    rows => 1,
    'for' => 'update'
});

my $id_before_update = $rs->first->id;

my $updated = $rs->update({
    status => 'reserved'
});

$guard->commit;

my $id_at_end = $rs->first->id;

print "id before update: $id_before_update\nid at end: $id_at_end\n";