[dune-pdelab] Time-dependent right hand side

[conf86 at web.de]

> The local operator is the right place for time-dependent source/sink terms and
> Neumann boundary conditions.  Time-dependent Dirichlet boundary conditions
> need to be interpolated in each time step, usually the bcextension is reused
> for that.  See
> https://cgit.dune-project.org/repositories/dune-pdelab-howto/tree/src/course-examples/example03_bcextension.hh
> and
> https://cgit.dune-project.org/repositories/dune-pdelab-howto/tree/src/course-examples/example03_Q2.hh#n80
> line 80, observe how the BCExtension instance g is passed to osm.apply().

Ok, I think I understand that, my question is how to get the time parameter in local operator to define the time-dependent source term. 
void setTime() didn't work, possibly because I got the line wrong where it has to be put. If I try without I always get the "'time' was not declared in this scope" error.