code: def setup_module():
      global DATA
  
      DATA["empty_trk_fname"] = pjoin(data_path, "empty.trk")
      # simple.trk contains only streamlines
      DATA["simple_trk_fname"] = pjoin(data_path, "simple.trk")
      # standard.trk contains only streamlines
      DATA["standard_trk_fname"] = pjoin(data_path, "standard.trk")
      # standard.LPS.trk contains only streamlines
      DATA["standard_LPS_trk_fname"] = pjoin(
          data_path, "standard.LPS.trk"
      )
  
      # complex.trk contains streamlines, scalars and properties
      DATA["complex_trk_fname"] = pjoin(data_path, "complex.trk")
      DATA["complex_trk_big_endian_fname"] = pjoin(
          data_path, "complex_big_endian.trk"
      )
  
      DATA["streamlines"] = [
          np.arange(1 * 3, dtype="f4").reshape((1, 3)),
          np.arange(2 * 3, dtype="f4").reshape((2, 3)),
          np.arange(5 * 3, dtype="f4").reshape((5, 3)),
      ]
  
      DATA["fa"] = [
          np.array([[0.2]], dtype="f4"),
          np.array([[0.3], [0.4]], dtype="f4"),
          np.array([[0.5], [0.6], [0.6], [0.7], [0.8]], dtype="f4"),
      ]
  
      DATA["colors"] = [
          np.array([(1, 0, 0)] * 1, dtype="f4"),
          np.array([(0, 1, 0)] * 2, dtype="f4"),
          np.array([(0, 0, 1)] * 5, dtype="f4"),
      ]
  
      DATA["mean_curvature"] = [
          np.array([1.11], dtype="f4"),
          np.array([2.11], dtype="f4"),
          np.array([3.11], dtype="f4"),
      ]
  
      DATA["mean_torsion"] = [
          np.array([1.22], dtype="f4"),
          np.array([2.22], dtype="f4"),
          np.array([3.22], dtype="f4"),
      ]
  
      DATA["mean_colors"] = [
          np.array([1, 0, 0], dtype="f4"),
          np.array([0, 1, 0], dtype="f4"),
          np.array([0, 0, 1], dtype="f4"),
      ]
  
      DATA["data_per_point"] = {
          "colors": DATA["colors"],
          "fa": DATA["fa"],
      }
      DATA["data_per_streamline"] = {
          "mean_curvature": DATA["mean_curvature"],
          "mean_torsion": DATA["mean_torsion"],
          "mean_colors": DATA["mean_colors"],
      }
  
      DATA["empty_tractogram"] = Tractogram(affine_to_rasmm=np.eye(4))
      DATA["simple_tractogram"] = Tractogram(
          DATA["streamlines"], affine_to_rasmm=np.eye(4)
      )
      DATA["complex_tractogram"] = Tractogram(
          DATA["streamlines"],
          DATA["data_per_streamline"],
          DATA["data_per_point"],
          affine_to_rasmm=np.eye(4),
      )
  
imports: import copy
  import os
  import sys
  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 assert_arr_dict_equal, clear_and_catch_warnings, data_path, error_warnings
  from ..None import trk
  from ..header import Field
  from ..tractogram import Tractogram
  from ..tractogram_file import HeaderError, HeaderWarning
  from ..trk import TrkFile, decode_value_from_name, encode_value_in_name, get_affine_trackvis_to_rasmm
  from .test_tractogram import assert_tractogram_equal
label_desc: Use image node_id 1 for calling a global function with example usage: setup_module() without return types