old_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  import commands
  import unittest
  
  from arc_test import ArcTest
  from incar_test import InCarTest
  from oszicar_test import OsziCarTest
  from outcar_test import OutCarTest
  from xsd_test import XsdTest
  from xtd_test import XtdTest
  
  def suite():
      suite = unittest.TestSuite([
          unittest.TestLoader().loadTestsFromTestCase(ArcTest),
          unittest.TestLoader().loadTestsFromTestCase(InCarTest),
          unittest.TestLoader().loadTestsFromTestCase(OsziCarTest),
          unittest.TestLoader().loadTestsFromTestCase(OutCarTest),
          unittest.TestLoader().loadTestsFromTestCase(XsdTest),
          unittest.TestLoader().loadTestsFromTestCase(XtdTest),
      ])
  
      return suite
  
  if "__main__" == __name__:
      result = unittest.TextTestRunner(verbosity=2).run(suite())
  
      if result.errors or result.failures:
          raise ValueError("Get errors and failures.")
  
  
new_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  import unittest
  
  from arc_test import ArcTest
  from incar_test import InCarTest
  from oszicar_test import OsziCarTest
  from outcar_test import OutCarTest
  from xsd_test import XsdTest
  from xtd_test import XtdTest
  
  def suite():
      suite = unittest.TestSuite([
          unittest.TestLoader().loadTestsFromTestCase(ArcTest),
          unittest.TestLoader().loadTestsFromTestCase(InCarTest),
          unittest.TestLoader().loadTestsFromTestCase(OsziCarTest),
          unittest.TestLoader().loadTestsFromTestCase(OutCarTest),
          unittest.TestLoader().loadTestsFromTestCase(XsdTest),
          unittest.TestLoader().loadTestsFromTestCase(XtdTest),
      ])
  
      return suite
  
  if "__main__" == __name__:
      result = unittest.TextTestRunner(verbosity=2).run(suite())
  
      if result.errors or result.failures:
          raise ValueError("Get errors and failures.")
  
  
subject: Remove redundant import.