code: def test_prepare_line():
      e = np.asarray([0, 1, 2, 3], dtype=int)
      n = np.asarray([[0, 1], [0, 2], [2, 3], [8, 9]], dtype=int)
      pe, pn = html_connectome._prepare_line(e, n)
      assert (pn == [0, 1, 0, 0, 2, 0, 2, 3, 0, 8, 9, 0]).all()
      assert (pe == [0, 0, 0, 1, 1, 0, 2, 2, 0, 3, 3, 0]).all()
  
file_path: nilearn/nilearn/plotting/tests/test_html_connectome.py
imports: import json
  import numpy
  import pytest
  from nilearn.plotting import html_connectome
  from nilearn.plotting.js_plotting_utils import decode
  from .test_js_plotting_utils import check_html
label_desc: Use image node_id 1 for calling a global function with example usage: test_prepare_line() without return types