code: def test_getitem(self):
      sliced = self.av[:10]
      np.testing.assert_almost_equal(
          sliced.q_values.array, self.q_values[:10]
      )
      np.testing.assert_equal(
          sliced.quantiles.array, self.quantiles[:10]
      )
      self.assertEqual(sliced.n_actions, self.action_size)
      self.assertIs(
          sliced.q_values_formatter, self.av.q_values_formatter
      )
  
imports: import unittest
  import chainer
  import chainer.functions
  from chainer import testing
  import numpy
  from chainerrl import action_value
label_desc: Use image node_id 5 for calling the TestQuantileDiscreteActionValue obj's underlying member method code with example usage: obj.test_getitem() without return types