docstr: Test of the parallel ccmbinator with a not none generator.
docstr_tok: ["Test","of","the","parallel","ccmbinator","with","a","not","none","generator","."]
code: def test_parallel_with_gen_not_none(self):
      """Test of the parallel ccmbinator with a not none generator."""
      dataset1 = lambda _: (i for i in range(10))
      dataset2 = lambda _: (i for i in range(10, 20))
      parallel = data.Parallel([dataset1, dataset2])
  
      def test_generator():
          yield 0
  
      generator = parallel(gen=test_generator)
  
      self.assertEqual(next(generator), 0)
      self.assertEqual(next(generator), 10)
      self.assertEqual(next(generator), 1)
      self.assertEqual(next(generator), 11)
      self.assertEqual(next(generator), 2)
      self.assertEqual(next(generator), 12)
  
imports: import itertools
  import os
  from absl.testing import absltest
  from absl.testing import parameterized
  import numpy
  from trax import data
label_desc: Use image node_id 11 for calling the InputsTest obj's underlying member method code with example usage: obj.test_parallel_with_gen_not_none() without return types