def test_equal_2(self):
     self.assertEqual(first_non_repeating_letter('stress'), 't')
 def test_equal_10(self):
     self.assertEqual(first_non_repeating_letter(
         "Go hang a salami, I'm a lasagna hog!"), ',')
 def test_equal_1(self):
     self.assertEqual(first_non_repeating_letter('a'), 'a')
 def test_equal_8(self):
     self.assertEqual(first_non_repeating_letter('hello world, eh?'), 'w')
 def test_equal_9(self):
     self.assertEqual(first_non_repeating_letter('sTreSS'), 'T')
 def test_equal_3(self):
     self.assertEqual(first_non_repeating_letter('moonmen'), 'e')
 def test_equal_7(self):
     self.assertEqual(first_non_repeating_letter('~><#~><'), '#')
 def test_equal_1(self):
     self.assertEqual(first_non_repeating_letter('a'), 'a')
 def test_equal_2(self):
     self.assertEqual(first_non_repeating_letter('stress'), 't')
 def test_equal_10(self):
     self.assertEqual(
         first_non_repeating_letter("Go hang a salami, I'm a lasagna hog!"),
         ',')
 def test_equal_9(self):
     self.assertEqual(first_non_repeating_letter('sTreSS'), 'T')
 def test_equal_8(self):
     self.assertEqual(first_non_repeating_letter('hello world, eh?'), 'w')
 def test_equal_7(self):
     self.assertEqual(first_non_repeating_letter('~><#~><'), '#')
 def test_equal_3(self):
     self.assertEqual(first_non_repeating_letter('moonmen'), 'e')