code: def testEmptyPool(self):
      p = Pool()
  
      YamlOutput(filename="test.yaml")(p)
  
      result = getYaml("test.yaml")
      expected = self.metadata + """"""
      self.assertEqual(result, expected)
  
imports: from essentia_test import *
  from essentia._essentia import version
  import os
  import json
label_desc: Use image node_id 15 for calling the TestYamlOutput obj's underlying member method code with example usage: obj.testEmptyPool() without return types