new_contents: import sys
  import os.path
  sys.path.insert(0, os.path.join(os.path.dirname(os.path.abspath(__file__)),
                                  '..', 'build', 'default', 'examples'))
  import foo
  import unittest
  
  
  class TestFoo(unittest.TestCase):
  
      def test_add_prefix(self):
          obj = foo.SomeObject("hello ")
          ln, msg = obj.add_prefix("gjc")
          self.assertEqual(msg, "hello gjc")
          self.assertEqual(ln, len("hello gjc"))
  
      def test_foo(self):
          f = foo.Foo("hello")
          self.assertEqual(f.get_datum(), "hello")
  
      def test_pass_foo_by_value(self):
          obj = foo.SomeObject("")
          f = foo.Foo("hello")
          obj.set_foo_value(f)
  
          f2 = obj.get_foo_value()
          self.assertEqual(f2.get_datum(), "hello")
  
      def test_pass_foo_by_transfer_ptr(self):
          obj = foo.SomeObject("")
          f = foo.Foo("hello")
          obj.set_foo_ptr(f)
          del f
          f2 = obj.get_foo_ptr()
          self.assertEqual(f2.get_datum(), "hello")
          
      def test_pass_foo_shared_ptr(self):
          obj = foo.SomeObject("")
          f = foo.Foo("hello")
          obj.set_foo_shared_ptr(f)
          self.assertEqual(f.get_datum(), "hello")
          f2 = obj.get_foo_shared_ptr()
          self.assertEqual(f2.get_datum(), "hello")
      
          
          
  if __name__ == '__main__':
      unittest.main()
  
subject: add some unit tests for the built example