text: import unittest
  
  from katas.beta.reverse_complement_dna import reverse_complement
  
  
  class ReverseComplementTestCase(unittest.TestCase):
      def test_equal_1(self):
          self.assertEqual(reverse_complement('TTCCGGAA'), 'TTCCGGAA')
  
      def test_equal_2(self):
          self.assertEqual(reverse_complement('GACTGACTGTA'), 'TACAGTCAGTC')
  
      def test_equal_3(self):
          self.assertEqual(reverse_complement(''), '')
  
      def test_equal_4(self):
          self.assertEqual(reverse_complement('XYZ'), 'Invalid sequence')
  