def test_equal_2(self):
     self.assertEqual(reverse_complement('GACTGACTGTA'), 'TACAGTCAGTC')
 def test_equal_4(self):
     self.assertEqual(reverse_complement('XYZ'), 'Invalid sequence')
 def test_equal_1(self):
     self.assertEqual(reverse_complement('TTCCGGAA'), 'TTCCGGAA')
 def test_equal_3(self):
     self.assertEqual(reverse_complement(''), '')