docstr: Test of the parallel ccmbinator with weights.
docstr_tok: ["Test","of","the","parallel","ccmbinator","with","weights","."]
code: def test_parallel_with_weights(self):
      """Test of the parallel ccmbinator with weights."""
      dataset1 = lambda: (i for i in range(10))
      dataset2 = lambda: (i for i in range(10, 20))
      parallel = data.Parallel([dataset1, dataset2], counters=(2, 1))
      generator = parallel()
  
      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), 3)
      self.assertEqual(next(generator), 12)
      self.assertEqual(next(generator), 4)
      self.assertEqual(next(generator), 5)
      self.assertEqual(next(generator), 13)
  
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 12 for calling the InputsTest obj's underlying member method code with example usage: obj.test_parallel_with_weights() without return types