code: def setup_module():
      global f1, f2
      fname = get_fnames("fornix")
      fornix = load_tractogram(fname, "same", bbox_valid_check=False)
  
      # Should work with both StatefulTractogram and streamlines (list of array)
      f1 = fornix[:200]
      f2 = fornix.streamlines[200:]
  
file_path: dipy/dipy/segment/tests/test_fss.py
imports: import numpy
  from dipy.data import get_fnames
  from dipy.io.streamline import load_tractogram
  from dipy.segment.fss import FastStreamlineSearch, nearest_from_matrix_row, nearest_from_matrix_col
  from dipy.segment.metric import mean_euclidean_distance
  from dipy.testing import assert_arrays_equal, assert_greater, assert_greater_equal, assert_true
  from numpy.testing import assert_almost_equal, assert_raises
label_desc: Use image node_id 1 for calling a global function with example usage: setup_module() without return types