old_contents: import unittest
  
  class TestTtFmt(unittest.TestCase):
  
      def testName(self):
          pass
  
  if __name__ == "__main__":
      unittest.main()
new_contents: import unittest
  
  import tt.fmttools.ttfmt as ttfmt
  
  class TestTtFmt(unittest.TestCase):
  
      def test_get_vars(self):
          data_provider = {
                           # Simple test cases
                           "F = A and B" : ["F", "A", "B"],
                           "F = A and B or C" : ["F", "A", "B", "C"],
                           }
          
          for eq in data_provider:
              self.assertListEqual(data_provider[eq], ttfmt.get_vars(eq))
  
  if __name__ == "__main__":
      unittest.main()
subject: Add basic tests for ttfmt get_vars method