text: '''
  https://docs.python.org/3/library/unittest.html
  
  
  A module in python is a file containing Python definitions
  and statements.
  
  A xxx.py file is a module
  
  '''
  import unittest
  
  # make a test class inherent unittest.TestCase
  class TestStringMethods(unittest.TestCase):
  
      def test_upper(self):
          self.assertEqual('foo'.upper(), 'FOO')
  
      def test_isupper(self):
          self.assertTrue('FOO'.isupper())
          self.assertFalse('Foo'.isupper())
  
      def test_split(self):
          s = 'hello world'
          self.assertEqual(s.split(), ['hello', 'world'])
          # check that s.split fails when the separator is not a string
          with self.assertRaises(TypeError):
              s.split(2)
  
      def test_dummy(self):
          self.assertTrue(True)        
  
  
  if __name__ == '__main__':
      unittest.main()