Periodic BC with DG spaces

General Discussion
1

Is it possible to implement bi-periodic condition for solving a pde on a 1 by 1 square which is discretized by H(div),RT space functions in freeFEM?

2

Yes, but I never try.

mesh Th=square(50,50);
fespace Vh(Th,RT0,periodic=[[1,x],[3,x],[2,y],[4,y]]);

Vh [u1,u2]=[sin(x2pi),cos(y2pi)];
plot([u1,u2],wait=1);