File laplacexy2.hxx# class LaplaceXY2# #include <laplacexy2.hxx> Create a dummy class so that code will compile without PETSc, but will throw an exception if LaplaceXY is used. Public Functions inline LaplaceXY2(Mesh *m = nullptr, Options *opt = nullptr, const CELL_LOC loc = CELL_CENTRE)# inline void setCoefs(const Field2D &A, const Field2D &B)# inline Field2D solve(const Field2D &rhs, const Field2D &x0)#