new_contents: from __future__ import absolute_import
  
  import unittest
  
  import servy.exc
  
  
  class StringRepresentation(unittest.TestCase):
      def test_service_not_found_str_repr(self):
          exception = servy.exc.ServiceNotFound('serv')
          self.assertEqual(str(exception), 'serv')
  
      def test_procedure_not_found_str_repr(self):
          exception = servy.exc.ProcedureNotFound('serv')
          self.assertEqual(str(exception), 'serv')
  
subject: add exceptions test