text: import unittest
  
  from pizza_utils import stringutils
  
  class FindFromTestCase(unittest.TestCase):
      def test_worst_case(self):
          expected = (0, "a")
          actual = stringutils.find_from("abcd", ("d", "c", "b", "a"))
  
          self.assertEqual(expected, actual)
      
      def test_duplicate(self):
          expected = (0, "sub")
          actual = stringutils.find_from("sub", ("sub", "su", "s"))
  
          self.assertEqual(expected, actual)
  
      def test_notfound(self):
          expected = (-1, None)
          actual = stringutils.find_from("therearenosubstrings", ("x", "y", "z"))
  
          self.assertEqual(expected, actual)
  
  if __name__ == "__main__":
      unittest.main()
  