docs: @Override
      public DMatrixRMaj getQ(DMatrixRMaj Q , boolean compact ) {
          if( compact ) {
              Q = UtilDecompositons_DDRM.checkIdentity(Q,numRows,minLength);
          } else {
              Q = UtilDecompositons_DDRM.checkIdentity(Q,numRows,numRows);
          }
  
          for( int j = minLength-1; j >= 0; j-- ) {
              double u[] = dataQR[j];
  
              double vv = u[j];
              u[j] = 1;
              QrHelperFunctions_DDRM.rank1UpdateMultR(Q, u, gammas[j], j, j, numRows, v);
              u[j] = vv;
          }
  
          return Q;
      }