code: def _write_multiple_hdfs_pq_files(self, tmpdir):
      import pyarrow.parquet as pq
  
      nfiles = 10
      size = 5
      test_data = []
      for i in range(nfiles):
          df = _test_dataframe(size, seed=i)
  
          df["index"] = np.arange(i * size, (i + 1) * size)
  
          # Hack so that we don't have a dtype cast in v1 files
          df["uint32"] = df["uint32"].astype(np.int64)
  
          path = pjoin(tmpdir, "{}.parquet".format(i))
  
          table = pa.Table.from_pandas(df, preserve_index=False)
          with self.hdfs.open(path, "wb") as f:
              pq.write_table(table, f)
  
          test_data.append(table)
  
      expected = pa.concat_tables(test_data)
      return expected
  
imports: import os
  import random
  from io import BytesIO
  from os.path import join
  import numpy
  import pytest
  import pyarrow
  from pyarrow.tests import util
  from pyarrow.tests.parquet.common import _test_dataframe
  from pyarrow.tests.parquet.test_dataset import _test_write_to_dataset_with_partitions, _test_write_to_dataset_no_partitions
  from pyarrow.util import guid
label_desc: Use image node_id 20 for calling the HdfsTestCases obj's underlying member method code with example usage: obj._write_multiple_hdfs_pq_files(tmpdir) and returns: expected