code: def test_read_multiple_files(
      self, tmp_path, block_type, ray_start_regular_shared
  ):
      path1 = os.path.join(tmp_path, "1970", "fr", "data.csv")
      write_csv({"number": [1, 2, 3]}, path1)
      path2 = os.path.join(tmp_path, "1971", "ir", "data.csv")
      write_csv({"number": [4, 5, 6]}, path2)
  
      ds = read_csv(
          [path1, path2],
          partitioning=Partitioning(
              "dir", field_names=["year", "country"], base_dir=tmp_path
          ),
          block_type=block_type,
      )
  
      df = ds.to_pandas()
      assert list(df.columns) == ["number", "year", "country"]
      assert list(df[df["year"] == "1970"]["number"]) == [1, 2, 3]
      assert list(df[df["year"] == "1970"]["country"]) == [
          "fr",
          "fr",
          "fr",
      ]
      assert list(df[df["year"] == "1971"]["number"]) == [4, 5, 6]
      assert list(df[df["year"] == "1971"]["country"]) == [
          "ir",
          "ir",
          "ir",
      ]
  
imports: import json
  import os
  import posixpath
  from typing import Any, Callable, Dict, Iterator, List, Optional, Union
  import pandas
  import pyarrow
  import pyarrow
  import pytest
  from pyarrow.fs import FileType
  from pytest_lazyfixture import lazy_fixture
  import ray
  from ray.data.block import Block
  from ray.data.dataset import Dataset
  from ray.data.datasource import FileBasedDatasource, PathPartitionParser
  from ray.data.datasource.file_based_datasource import FileExtensionFilter, _resolve_paths_and_filesystem
  from ray.data.datasource.partitioning import Partitioning, PartitionStyle, PathPartitionFilter
  from ray.data.tests.conftest import *
  from ray.tests.conftest import *
label_desc: Use image node_id 7 for calling the TestReadDirPartitionedFiles obj's underlying member method code with example usage: obj.test_read_multiple_files(tmp_path, block_type, ray_start_regular_shared) without return types