title: What are typical uses cases for Test Execution Listeners in Testing Frameworks such as JUnit and TestNG?
body: <p>JUnit,TestNG, and Spring testing have test execution listeners as an extension mechanism. Test execution listeners seem to be a low level feature of interest to framework developers and tool developers. </p>
  
  <p>What are the main use cases in which Test execution listeners are useful?  Can they be useful to application developers?</p>