code: def test_stats_gen_with_invalid_csv_header_in_multiple_files(self):
      records, _, _ = self._get_csv_test(
          delimiter=",", with_header=True
      )
      header = records.pop(0)
      # Split the records into two subsets and write to separate files.
      records1 = [header] + records[0:3]
      records2 = ["random,header"] + records[3:]
      tmp_dir = self._get_temp_dir()
      self._write_records_to_csv(records1, tmp_dir, "input_data1.csv")
      self._write_records_to_csv(records2, tmp_dir, "input_data2.csv")
      input_data_path = os.path.join(tmp_dir, "input_data*")
  
      with self.assertRaisesRegexp(
          ValueError, "Files have different headers."
      ):
          _ = stats_gen_lib.generate_statistics_from_csv(
              data_location=input_data_path,
              column_names=None,
              delimiter=",",
          )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import gzip
  import os
  import tempfile
  from absl.testing import absltest
  from absl.testing import parameterized
  from apache_beam.io.filesystem import CompressionTypes
  import pandas
  import tensorflow
  from tensorflow_data_validation.statistics import stats_options
  from tensorflow_data_validation.utils import stats_gen_lib
  from tensorflow_data_validation.utils import test_util
  from google.protobuf import text_format
  from tensorflow_metadata.proto.v0 import schema_pb2
  from tensorflow_metadata.proto.v0 import statistics_pb2
label_desc: Use image node_id 13 for calling the StatsGenTest obj's underlying member method code with example usage: obj.test_stats_gen_with_invalid_csv_header_in_multiple_files() without return types