code: def test_read_files(self):
      self._write_tfrecord("train", 4, "abcdefghijkl")
      filename_template = self._filename_template(split="train")
      ds = self.reader.read_files(
          [
              shard_utils.FileInstruction(
                  filename=os.fspath(
                      filename_template.sharded_filepath(
                          shard_index=1, num_shards=4
                      )
                  ),
                  skip=0,
                  take=-1,
                  examples_in_shard=3,
              ),
              shard_utils.FileInstruction(
                  filename=os.fspath(
                      filename_template.sharded_filepath(
                          shard_index=3, num_shards=4
                      )
                  ),
                  skip=1,
                  take=1,
                  examples_in_shard=3,
              ),
          ],
          read_config=read_config_lib.ReadConfig(),
          shuffle_files=False,
      )
      read_data = list(tfds.as_numpy(ds))
      self.assertEqual(
          read_data, [bytes(l, encoding="utf-8") for l in "defk"]
      )
  
imports: import functools
  import itertools
  import os
  from unittest import mock
  import tensorflow
  import tensorflow_datasets
  from tensorflow_datasets import testing
  from tensorflow_datasets.core import example_parser
  from tensorflow_datasets.core import naming
  from tensorflow_datasets.core import reader
  from tensorflow_datasets.core import splits
  from tensorflow_datasets.core import writer
  from tensorflow_datasets.core.utils import read_config
  from tensorflow_datasets.core.utils import shard_utils
label_desc: Use image node_id 11 for calling the ReaderTest obj's underlying member method code with example usage: obj.test_read_files() without return types