code: def test_apply_transform_to_key_from_config(self):
      dataset = self.get_test_image_dataset(SampleType.DICT)
  
      config = [
          {
              "name": "apply_transform_to_key",
              "transforms": [{"name": "ToTensor"}],
              "key": "input",
          }
      ]
      transform = build_transforms(config)
      sample = dataset[0]
      expected_sample = _apply_transform_to_key_and_copy(
          sample, transforms.ToTensor(), "input"
      )
      self.transform_checks(sample, transform, expected_sample)
  
file_path: ClassyVision/test/dataset_transforms_util_test.py
imports: import copy
  import random
  import unittest
  import numpy
  import torch
  import torchvision.transforms
  from classy_vision.dataset.core.random_image_datasets import RandomImageBinaryClassDataset, SampleType
  from classy_vision.dataset.transforms import build_transforms
  from classy_vision.dataset.transforms.util import build_field_transform_default_imagenet, GenericImageTransform, ImagenetAugmentTransform, ImagenetNoAugmentTransform
label_desc: Use image node_id 5 for calling the DatasetTransformsUtilTest obj's underlying member method code with example usage: obj.test_apply_transform_to_key_from_config() without return types