def test_iadd(self, evt):
        rval = event.ReturnValue(append_events=[evt])
        rval2 = event.ReturnValue(eat=True, append_events=[evt])
        rset = event.ResultSet()

        rset += rval
        rset += rval2
        rset += None
        assert rset.eat
        assert rset.append_events == [evt, evt]
def _maybe_name(obj):
  """Returns object name if it has one, or a message otherwise.

  This is useful for names that apper in error messages.
  Args:
    obj: Object to get the name of.
  Returns:
    name, "None", or a "no name" message.
  """
  if obj is None:
    return "None"
  elif hasattr(obj, "name"):
    return obj.name
  else:
    return "<no name for %s>" % type(obj)