old_contents: import os
  import subprocess
  import sys
  from queue import Queue
  
  sys.path.insert(0, ".")
  import unittest
  from bears.tests.LocalBearTestHelper import LocalBearTestHelper
  from bears.css.CSSLintBear import CSSLintBear
  from coalib.settings.Section import Section
  
  
  class CSSLintBearTest(LocalBearTestHelper):
      def setUp(self):
          self.section = Section("test section")
          self.uut = CSSLintBear(self.section, Queue())
          self.test_file1 = os.path.join(os.path.dirname(__file__),
                                         "test_files",
                                         "csslint_test1.css")
          self.test_file2 = os.path.join(os.path.dirname(__file__),
                                         "test_files",
                                         "csslint_test2.css")
  
      def test_run(self):
          # Test a file without any issues
          self.assertLinesValid(self.uut, [], self.test_file1)
  
          # Test a file with errors and warnings
          self.assertLinesInvalid(self.uut, [], self.test_file2)
  
  
  def skip_test():
      try:
          subprocess.Popen(['csslint', '--version'],
                           stdout=subprocess.PIPE,
                           stderr=subprocess.PIPE)
          return False
      except OSError:
          return "csslint is not installed."
  
  
  if __name__ == '__main__':
      unittest.main(verbosity=2)
  
new_contents: import os
  import sys
  from queue import Queue
  from shutil import which
  from unittest.case import skipIf
  
  sys.path.insert(0, ".")
  import unittest
  from bears.tests.LocalBearTestHelper import LocalBearTestHelper
  from bears.css.CSSLintBear import CSSLintBear
  from coalib.settings.Section import Section
  
  
  @skipIf(which('csslint') is None, 'csslint is not installed')
  class CSSLintBearTest(LocalBearTestHelper):
      def setUp(self):
          self.section = Section("test section")
          self.uut = CSSLintBear(self.section, Queue())
          self.test_file1 = os.path.join(os.path.dirname(__file__),
                                         "test_files",
                                         "csslint_test1.css")
          self.test_file2 = os.path.join(os.path.dirname(__file__),
                                         "test_files",
                                         "csslint_test2.css")
  
      def test_run(self):
          # Test a file without any issues
          self.assertLinesValid(self.uut, [], self.test_file1)
  
          # Test a file with errors and warnings
          self.assertLinesInvalid(self.uut, [], self.test_file2)
  
  
  if __name__ == '__main__':
      unittest.main(verbosity=2)
  
subject: Use unittest skipIf