message: Added missed const
diff: @@ -1992,7 +1992,7 @@ void SparseMatrix::SetSubMatrixTranspose(const Array<int> &rows,
  }
  void SparseMatrix::GetSubMatrix(const Array<int> &rows, const Array<int> &cols,
  - DenseMatrix &subm)
  + DenseMatrix &subm) const
  {
  int i, j, gi, gj, s, t;
  double a;
  