title: How do I unit test Protocol and it's extension
body: <p>I have a protocol and I have it's definition in extension.</p>
  <p>I'd like to unit test the definition.</p>
  <p>I googled but I couldn't find anything relevant.</p>
  <p>The closest one I get is Mocking with Protocol or POP etc..</p>
  <p>If someone could explain me with a sample , it'd be great.</p>