docs: public static LinearSolverDense<DMatrixRMaj> leastSquares(int numRows , int numCols ) {
          if(numCols < EjmlParameters.SWITCH_BLOCK64_QR )  {
              return new LinearSolverQrHouseCol_DDRM();
          } else {
              if( EjmlParameters.MEMORY == EjmlParameters.MemoryUsage.FASTER )
                  return new LinearSolverQrBlock64_DDRM();
              else
                  return new LinearSolverQrHouseCol_DDRM();
          }
      }