code: def test_load_multiline_header_file(self):
      for lazy_load in [False, True]:
          tck = TckFile.load(
              DATA["multiline_header_fname"], lazy_load=lazy_load
          )
          streamlines = list(tck.tractogram.streamlines)
          assert len(tck.header["command_history"].splitlines()) == 3
          assert len(streamlines) == 1
          assert streamlines[0].shape == (253, 3)
  
imports: import os
  import unittest
  from io import BytesIO
  from os.path import join
  import numpy
  import pytest
  from numpy.testing import assert_array_equal
  from ...testing import data_path, error_warnings
  from ..None import tck
  from ..array_sequence import ArraySequence
  from ..tck import TckFile
  from ..tractogram import Tractogram
  from ..tractogram_file import DataError, HeaderError, HeaderWarning
  from .test_tractogram import assert_tractogram_equal
label_desc: Use image node_id 7 for calling the TestTCK obj's underlying member method code with example usage: obj.test_load_multiline_header_file() without return types