template < class DT, class KF >
void HashTbl<DT,KF>:: showStructure() const
{
    for ( int i=0; i<tableSize; i++ )
    {
        cout << i << ": ";
        if ( dataTable[i].isEmpty() )
            cout << "_";
        else
        {
            dataTable[i].gotoBeginning();
            do
            {
                cout << dataTable[i].getCursor().getKey() << " ";
            } while ( dataTable[i].gotoNext() );
        }
        cout << endl << endl;
    }
}