code: def test_dict_array_callable_tuple(self):
      dataset = tabular.from_data(
          {"a": np.arange(10), ("b", "c"): lambda i: (i * i, -i)}
      )
  
      self.assertIsInstance(dataset, chainer.dataset.TabularDataset)
      self.assertEqual(len(dataset), 10)
      self.assertEqual(set(dataset.keys), {"a", "b", "c"})
      self.assertEqual(dataset.mode, dict)
  
      output = dataset.slice[[1, 3]].fetch()
      np.testing.assert_equal(
          output, {"a": [1, 3], "b": [1, 9], "c": [-1, -3]}
      )
      self.assertIsInstance(output["a"], np.ndarray)
      self.assertIsInstance(output["b"], list)
      self.assertIsInstance(output["c"], list)
  
imports: import unittest
  import numpy
  import chainer
  from chainer.dataset import tabular
  from chainer import testing
label_desc: Use image node_id 21 for calling the TestFromData obj's underlying member method code with example usage: obj.test_dict_array_callable_tuple() without return types