radiation_compute_external Subroutine

   subroutine radiation_compute_external(mesh, context, state, source)
      type(mesh_t), intent(in) :: mesh
      type(radiation_context_t), intent(in) :: context
      type(radiation_state_t), intent(in) :: state
      type(radiation_source_t), intent(inout) :: source
      associate(dummy_mesh => mesh%ncells, dummy_rank => context%rad_rank, dummy_step => state%step)
      end associate
      source%qrad = zero
   end subroutine radiation_compute_external