old_contents: import time
  from .util import (DestructiveYubikeyTestCase, ykman_cli)
  
  
  class TestYkmanInfo(DestructiveYubikeyTestCase):
  
      def test_ykman_info(self):
          time.sleep(3)
          info = ykman_cli('info')
          self.assertIn('Device type:', info)
          self.assertIn('Serial number:', info)
          self.assertIn('Firmware version:', info)
  
new_contents: from .util import (DestructiveYubikeyTestCase, ykman_cli)
  
  
  class TestYkmanInfo(DestructiveYubikeyTestCase):
  
      def test_ykman_info(self):
          info = ykman_cli('info')
          self.assertIn('Device type:', info)
          self.assertIn('Serial number:', info)
          self.assertIn('Firmware version:', info)
  
subject: Remove unnecessary sleep