sub begin_work {
    use Data::Dumper;
    my $self = shift;
    my ($obj) = @_;

    unless ($self->supports('transactions')) {
        DBM::Deep->_throw_error( "Cannot begin_work unless transactions are supported" );
    }

    if ( $self->trans_id ) {
        DBM::Deep->_throw_error( "Cannot begin_work within an active transaction" );
    }

    my @slots = $self->read_txn_slots;
    print Dumper(@slots);
    my $found;
    for my $i ( 0 .. $self->num_txns-2 ) {
        print  "i,$i\n";
        next if $slots[$i];

        $slots[$i] = 1;
        $self->set_trans_id( $i + 1 );
        $found = 1;
        last;
    }
    unless ( $found ) {
        DBM::Deep->_throw_error( "Cannot allocate transaction ID" );
    }
    $self->write_txn_slots( @slots );

    if ( !$self->trans_id ) {
        DBM::Deep->_throw_error( "Cannot begin_work - no available transactions" );
    }

    no Data::Dumper;
    return;
}