new_contents: from butter.eventfd import Eventfd
  from butter.fanotify import Fanotify
  from butter.inotify import Inotify
  from butter.signalfd import Signalfd
  from butter.timerfd import Timerfd
  import pytest
  
  
  @pytest.fixture(params=[Eventfd, Fanotify, Inotify, Signalfd, Timerfd])
  def obj(request):
      Obj = request.param
      o = Obj.__new__(Obj)
      
      return o
  
  @pytest.mark.repr
  @pytest.mark.unit
  def test_repr_name(obj):
      obj._fd = 1
      assert obj.__class__.__name__ in repr(obj), "Instance's representation does not contain its own name"
  
  @pytest.mark.repr
  @pytest.mark.unit
  def test_repr_fd(obj):
      obj._fd = 1
      assert 'fd=1' in repr(obj), "Instance does not list its own fd (used for easy identifcation)"
      
  
  @pytest.mark.repr
  @pytest.mark.unit
  def test_repr_fd_closed(obj):
      obj._fd = None
      assert 'fd=closed' in repr(obj), "Instance does not indicate it is closed"
  
subject: Test the repr() of object