docs: public DMatrixRMaj getQ(DMatrixRMaj Q ) {
          Q = UtilDecompositons_DDRM.checkIdentity(Q,N,N);
  
          for( int i = 0; i < N; i++ ) w[i] = 0;
  
          for( int j = N-2; j >= 0; j-- ) {
              w[j+1] = 1;
              for( int i = j+2; i < N; i++ ) {
                  w[i] = QT.get(j,i);
              }
              QrHelperFunctions_DDRM.rank1UpdateMultR(Q, w, gammas[j + 1], j + 1, j + 1, N, b);
  //            Q.print();
          }
  
          return Q;
      }