code: def testSingleKeySingleString(self):
      testFile = 'foo: "herro"'
      writeFile(testFile, "testfile")
  
      p = YamlInput(filename="testfile")()
      os.remove("testfile")
  
      self.assertEqual(p["foo"], "herro")
  
      testJson = '{ "foo": "herro" }'
      writeFile(testJson, "testfile")
  
      p = YamlInput(filename="testfile", format="json")()
      os.remove("testfile")
  
      self.assertEqual(p["foo"], "herro")
  
imports: from essentia_test import *
  import os
label_desc: Use image node_id 2 for calling the TestYamlInput obj's underlying member method code with example usage: obj.testSingleKeySingleString() without return types