code: def test_user_warning(self):
      dataset = numpy.ones((4, 6))
      iterator = self.iterator_class(dataset, 2, repeat=self.repeat)
      if self.repeat:
          with testing.assert_warns(UserWarning):
              extensions.Evaluator(iterator, {})
  
imports: import unittest
  import numpy
  import chainer
  from chainer import backend
  from chainer.backends import _cpu
  from chainer import dataset
  from chainer import iterators
  from chainer import testing
  from chainer.training import extensions
label_desc: Use image node_id 1 for calling the TestEvaluatorRepeat obj's underlying member method code with example usage: obj.test_user_warning() without return types