docs: public static double innerProdRow(int blockLength,
                                        DSubmatrixD1 A,
                                        int rowA,
                                        DSubmatrixD1 B,
                                        int rowB, int zeroOffset ) {
          int offset = rowA + zeroOffset;
          if( offset + B.col0 >= B.col1 )
              return 0;
  
          // take in account the one in 'A'
          double total = B.get(rowB,offset);
  
          total += VectorOps_DDRB.dot_row(blockLength,A,rowA,B,rowB,offset+1,A.col1-A.col0);
  
          return total;
      }