public OleDbSchemaReader(OleDbConnection connection,
                          ITableEnumerator tableEnumerator           = null,
                          ITableColumnExtractor tableColumnExtractor = null,
                          ITableIndexExtractor tableIndexExtractor   = null)
     : this(new OleDbConnectionWrapper(connection), tableEnumerator, tableColumnExtractor, tableIndexExtractor)
 {
 }
 internal OleDbSchemaReader(
     IOleDbConnectionWrapper connection,
     ITableEnumerator tableEnumerator,
     ITableColumnExtractor tableColumnExtractor,
     ITableIndexExtractor tableIndexExtractor)
 {
     _tableEnumerator      = tableEnumerator ?? new OleDbTableEnumerator(connection);
     _tableColumnExtractor = tableColumnExtractor ?? new OleDbTableColumnExtractor(connection);
     _tableIndexExtractor  = tableIndexExtractor ?? new OleDbTableIndexExtractor(connection);
 }