Method wait

src/test/msgr/test_async_networkstack.cc:108–115

      done = true;
    }
    void wait() {
      int us = 1000 * 1000 * 1000;
      while (!done) {
        ASSERT_TRUE(us > 0);
        usleep(100);
        us -= 100;
      }
    }
  };
  template<typename func>
  void exec_events(func &&f) {