code: def test_changing_dtype():
      batch_size = 2
      src_data = [
          [np.ones((120, 120, 3), dtype=np.float32)] * batch_size,
          [np.ones((120, 120, 3), dtype=np.uint8)] * batch_size,
      ]
      src_pipe = Pipeline(batch_size, 1, 0)
      src_ext = fn.external_source(source=src_data)
      src_pipe.set_outputs(src_ext)
      src_pipe.build()
      src_pipe.run()
      src_pipe.run()
  
imports: import random
  import nvidia.dali.fn
  import nvidia.dali.ops
  import nvidia.dali.types
  import numpy
  from nvidia.dali import Pipeline, pipeline_def
  from test_utils import check_batch
  from nose_utils import raises, assert_warns, assert_raises
  from nvidia.dali.types import DALIDataType
  from numpy.random import default_rng
label_desc: Use image node_id 15 for calling a global function with example usage: test_changing_dtype() without return types