void
addBs(SV *a_sv, std::vector<SV*> &b_svs)
{
  SV *tmpSv;
  I32 count;
  std::vector<SV*>::iterator iter;
  dSP;
  ENTER;
  SAVETMPS;
  PUSHMARK(SP);
  tmpSv = sv_mortalcopy(a_sv);
  XPUSHs(tmpSv);
  for (iter = b_svs.begin( ); iter != b_svs.end( ); ++iter) {
    XPUSHs(sv_2mortal(*iter));
  }
  PUTBACK;
  count = call_method("add", G_VOID|G_DISCARD);
  // A::add {
  //   my $this = shift;
  //   push(@{$this->{B}}, @_);
  // }
  SPAGAIN;
  assert(0 == count);
  FREETMPS;
  LEAVE;
}