code: def test_parquet_metadata_empty_to_dict(tempdir):
      # https://issues.apache.org/jira/browse/ARROW-10146
      table = pa.table({"a": pa.array([], type="int64")})
      pq.write_table(table, tempdir / "data.parquet")
      metadata = pq.read_metadata(tempdir / "data.parquet")
      # ensure this doesn't error / statistics set to None
      metadata_dict = metadata.to_dict()
      assert len(metadata_dict["row_groups"]) == 1
      assert len(metadata_dict["row_groups"][0]["columns"]) == 1
      assert (
          metadata_dict["row_groups"][0]["columns"][0]["statistics"]
          is None
      )
  
imports: import datetime
  import decimal
  from collections import OrderedDict
  import io
  import numpy
  import pytest
  import pyarrow
  from pyarrow.tests.parquet.common import _check_roundtrip, make_sample_file
  from pyarrow.fs import LocalFileSystem
  from pyarrow.tests import util
label_desc: Use image node_id 18 for calling a global function with example usage: test_parquet_metadata_empty_to_dict(tempdir) without return types