use DBI;
use Tie::Constrained;

our $dbh;
tie $dbh, 'Tie::Constrained' => {
    test => sub {
        $_[0]->isa('DBI::db')
            and $_[0]->ping;
    },
    value =>  DBI->connect('DBI:Mock:','','', \%attr),
    fail => sub {
        # warn  "Connecting $dsn . . .";
        $_[1] =
            DBI->connect($dsn, $user, $passwd, \%attr)
                or die $DBI::errstr;
    }
};

$dbh->{'mock_can_connect'} = 0;
$Tie::Constrained::STRICT = 1;