code: def test_get_source_target(source_name, target_name, download_path):
      source, target, num_channels = DigitDataset.get_source_target(
          DigitDataset(source_name),
          DigitDataset(target_name),
          download_path,
      )
      assert num_channels == 3
      assert isinstance(source, DigitDatasetAccess)
      assert isinstance(target, DigitDatasetAccess)
  
file_path: pykale/tests/loaddata/test_image_access.py
imports: import pytest
  import torch
  from numpy import testing
  from yacs.config import CfgNode
  from kale.loaddata.dataset_access import get_class_subset
  from kale.loaddata.image_access import DigitDataset, DigitDatasetAccess, get_cifar, ImageAccess
  from kale.loaddata.multi_domain import DomainsDatasetBase, MultiDomainAdapDataset, MultiDomainDatasets
label_desc: Use image node_id 4 for calling a global function with example usage: test_get_source_target(source_name, target_name, download_path) without return types