code: def _build(lhs, rhs):
      
      _check_under_condition()
      final_predicate, pred_set = _current_select()
      _check_and_add_pred_set(lhs, pred_set)
      _predicate_map.setdefault(lhs, []).append((final_predicate, rhs))
docs: Stores the wire assignment details until finalize is called.