text: import unittest
  from problem_21 import rooms, rooms_sorted
  
  
  class Problem21TestCase(unittest.TestCase):
      intervals = [(30, 75), (0, 50), (60, 150)]
  
      def test_rooms(self):
          self.assertEqual(2, rooms(self.intervals))
  
      def test_rooms_sorted(self):
          self.assertEqual(2, rooms_sorted(self.intervals))
  
  
  if __name__ == "__main__":
      unittest.main()
  