code: def setup():
      global DATA
      DATA["empty_filenames"] = [
          pjoin(data_path, "empty" + ext) for ext in FORMATS.keys()
      ]
      DATA["simple_filenames"] = [
          pjoin(data_path, "simple" + ext) for ext in FORMATS.keys()
      ]
      DATA["complex_filenames"] = [
          pjoin(data_path, "complex" + ext)
          for ext, cls in FORMATS.items()
          if (
              cls.SUPPORTS_DATA_PER_POINT
              or cls.SUPPORTS_DATA_PER_STREAMLINE
          )
      ]
  
      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)),
      ]
  
      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"),
      ]
  
      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"),
      ]
  
      mean_curvature = [
          np.array([1.11], dtype="f4"),
          np.array([2.11], dtype="f4"),
          np.array([3.11], dtype="f4"),
      ]
  
      mean_torsion = [
          np.array([1.22], dtype="f4"),
          np.array([2.22], dtype="f4"),
          np.array([3.22], dtype="f4"),
      ]
  
      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": colors, "fa": fa}
      DATA["data_per_streamline"] = {
          "mean_curvature": mean_curvature,
          "mean_torsion": mean_torsion,
          "mean_colors": 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 os
  import tempfile
  import unittest
  import warnings
  from io import BytesIO
  from os.path import join
  import numpy
  import pytest
  from numpy.compat.py3k import asbytes
  import nibabel
  from nibabel.testing import clear_and_catch_warnings, data_path, error_warnings
  from nibabel.tmpdirs import InTemporaryDirectory
  from ..None import FORMATS, trk
  from ..tractogram import LazyTractogram, Tractogram
  from ..tractogram_file import ExtensionWarning, TractogramFile
  from .test_tractogram import assert_tractogram_equal
label_desc: Use image node_id 1 for calling a global function with example usage: setup() without return types