code: def test_async_manager_basic(self):
      MyManager.register("Calculator", Calculator)
  
      manager = MyManager()
      manager.start()
  
      calc = manager.Calculator()
  
      res = calc.add(10, 32)
  
      assert res.get() == 42
  
      total = 4
      managers = [MyManager() for i in range(total)]
  
      [manager.start() for manager in managers]
  
      calculators = [manager.Calculator() for manager in managers]
  
      start_ts = time.time()
      handles = [calc.add_with_delay(10, 32) for calc in calculators]
  
      results = [handle.get() for handle in handles]
  
      duration = time.time() - start_ts
  
      assert duration < 2
      assert results == [42 for i in range(total)]
  
file_path: fiber/tests/test_managers.py
imports: import fiber
  import time
  import pytest
  import docker
  from fiber.managers import AsyncManager
label_desc: Use image node_id 3 for calling the TestManagers obj's underlying member method code with example usage: obj.test_async_manager_basic() without return types