code: def test_tuple_array_with_key_callable_unary(self):
      dataset = tabular.from_data(
          (("a", np.arange(10)), ("b", lambda i: i * i))
      )
  
      self.assertIsInstance(dataset, chainer.dataset.TabularDataset)
      self.assertEqual(len(dataset), 10)
      self.assertEqual(dataset.keys, ("a", "b"))
      self.assertEqual(dataset.mode, tuple)
  
      output = dataset.slice[[1, 3]].fetch()
      np.testing.assert_equal(output, ([1, 3], [1, 9]))
      self.assertIsInstance(output[0], np.ndarray)
      self.assertIsInstance(output[1], list)
  
imports: import unittest
  import numpy
  import chainer
  from chainer.dataset import tabular
  from chainer import testing
label_desc: Use image node_id 16 for calling the TestFromData obj's underlying member method code with example usage: obj.test_tuple_array_with_key_callable_unary() without return types