message: Visualized the marking.
diff: @@ -166,6 +166,20 @@ int main(int argc, char *argv[])
  ShiftedFaceMarker marker(pmesh, level_set, pfes_L2, false);
  level_set.ExchangeFaceNbrData();
  marker.MarkElements(elem_marker);
  + L2_FECollection fec_mark(0, dim);
  + ParFiniteElementSpace pfes_mark(&pmesh, &fec_mark);
  + ParGridFunction gf_mark(&pfes_mark);
  + for (int i = 0; i < gf_mark.Size(); i++) { gf_mark(i) = elem_marker[i]; }
  + if (visualization)
  + {
  + socketstream sol_sock_mark;
  + int size = 500;
  + char vishost[] = "localhost";
  + int visport = 19916;
  + common::VisualizeField(sol_sock_mark, vishost, visport, gf_mark,
  + "Marking", 0, size, size, size,
  + "rRjmm********A");
  + }
  ParBilinearForm lhs(&pfes_L2), rhs_bf(&pfes_L2);
  lhs.AddDomainIntegrator(new MassIntegrator);
  