old_contents: import unittest
  import simphony.engine as engine_api
  
  from simphony import CUDS
  from simlammps.lammps_wrapper import LammpsWrapper
  
  
  
  # TODO: Use an enum instead, defined in a proper place
  _LAMMPS = 'LAMMPS'
  _LIGGGHTS = 'LIGGGHTS'
  
  
  class TestPluginIntegration(unittest.TestCase):
      """Plugin integration tests."""
      def test_plugin_integration(self):
          from simphony.engine import lammps
          self.assertTrue(hasattr(lammps, 'LammpsWrapper'))
  
      def test_engine_registration(self):
          self.assertIn(_LAMMPS, engine_api.get_supported_engine_names())
          self.assertIn(_LIGGGHTS, engine_api.get_supported_engine_names())
  
      def test_lammps_creation(self):
          cuds = CUDS()
          lammps = engine_api.create_wrapper(cuds, _LAMMPS,
                                             engine_api.EngineInterface.Internal)
          self.assertIsInstance(lammps, LammpsWrapper)
  
          lammps = engine_api.create_wrapper(cuds, _LAMMPS,
                                             engine_api.EngineInterface.FileIO)
          self.assertIsInstance(lammps, LammpsWrapper)
  
      def test_liggghts_creation(self):
          cuds = CUDS()
          lights = engine_api.create_wrapper(cuds, _LIGGGHTS,
                                             engine_api.EngineInterface.FileIO)
          self.assertIsInstance(lights, LammpsWrapper)
  
          self.assertRaises(RuntimeError, engine_api.create_wrapper, cuds,
                            _LIGGGHTS,
                            engine_api.EngineInterface.Internal)
  
  
  if __name__ == '__main__':
      unittest.main()
  
new_contents: import unittest
  import simphony.engine as engine_api
  
  from simphony import CUDS
  from simlammps.lammps_wrapper import LammpsWrapper
  
  
  # TODO: Use an enum instead, defined in a proper place
  _LAMMPS = 'LAMMPS'
  _LIGGGHTS = 'LIGGGHTS'
  
  
  class TestPluginIntegration(unittest.TestCase):
      """Plugin integration tests."""
      def test_plugin_integration(self):
          from simphony.engine import lammps
          self.assertTrue(hasattr(lammps, 'LammpsWrapper'))
  
      def test_engine_registration(self):
          self.assertIn(_LAMMPS, engine_api.get_supported_engine_names())
          self.assertIn(_LIGGGHTS, engine_api.get_supported_engine_names())
  
      def test_lammps_creation(self):
          cuds = CUDS()
          lammps = engine_api.create_wrapper(cuds, _LAMMPS,
                                             engine_api.EngineInterface.Internal)
          self.assertIsInstance(lammps, LammpsWrapper)
  
          lammps = engine_api.create_wrapper(cuds, _LAMMPS,
                                             engine_api.EngineInterface.FileIO)
          self.assertIsInstance(lammps, LammpsWrapper)
  
      def test_liggghts_creation(self):
          cuds = CUDS()
          lights = engine_api.create_wrapper(cuds, _LIGGGHTS,
                                             engine_api.EngineInterface.FileIO)
          self.assertIsInstance(lights, LammpsWrapper)
  
          self.assertRaises(RuntimeError, engine_api.create_wrapper, cuds,
                            _LIGGGHTS,
                            engine_api.EngineInterface.Internal)
  
  
  if __name__ == '__main__':
      unittest.main()
  
subject: Remove extra line