Added code snippet in chap2.md for unittest module implementation

textbook/chap2.md

@@ -9,7 +9,7 @@ We are trying to build to-do list Django web app
   * Tends to track *User Story*
   * **Functional Test** == **Acceptance Test** == **End-to-End Test**
 
-Steps to create a FT for a MVP/A:
+Steps to create a FT for a MVP/A (Minimum Viable Product/App):
 
 1. Prepare a User Story (e.g. user story for to-do list)
 2. Add test assertions along user story, which is *expected fail*
@@ -23,6 +23,8 @@ python's default `assert` isn't helpful.
 
 `unittest` module of python standard library can be used
 
+Following are highlights of code snippet shown below:
+
 * tests can be organized into classes, which inherit from `unittest.TestCase`
 * `setUp` and `tearDown` are special methods that will be run before/after each test, even test failed
 * main body of tests is in `test_can_start_a_list_and_retrieve_it_later`. 
@@ -31,6 +33,24 @@ python's default `assert` isn't helpful.
 * Use `self.assertIn()` instead of `assert`. More helper functions like `assertEqual`, `assertTrue`, and `assertFalse` are available in *unittest*
 * `warning='ignore'` suppresses a superfluous `ResourceWarning`.
 
+```python
+class NewVisitorTest(unittest.TestCase):
+
+    def setUp(self):
+        self.browser = webdriver.Firefox()
+
+    def tearDown(self):
+        self.browser.quit()
+
+    def test_can_start_a_list_and_retrieve_it_later(self):
+        ...
+
+if __name__ == '__main__':
+    unittest.main(warnings='ignore')
+
+
+```
+
 Hence, a full cycle of test can be executed as it 
 
 1. Open Firefox