question: private void readSegments ( ) throws IOException { for ( SegmentExtent10 extent : _segmentExtents ) { try ( ReadStream is = openRead ( extent . address ( ) , extent . length ( ) ) ) { is . skip ( extent . length ( ) - BLOCK_SIZE ) ; long sequence = BitsUtil . readLong ( is ) ; byte [ ] tableKey = new byte [ TABLE_KEY_SIZE ] ; is . readAll ( tableKey , 0 , tableKey . length ) ; if ( sequence > 0 ) { Segment10 segment = new Segment10 ( sequence , tableKey , extent ) ; _segments . add ( segment ) ; } } } }
target:  Reads the segment metadata, the sequence and table key.