code: def generate_signal_crossing(
      gtab, lambda1, lambda2, lambda3, angle2=60
  ):
      mevals = np.array(
          ([lambda1, lambda2, lambda3], [lambda1, lambda2, lambda3])
      )
      angl = [(0, 0), (angle2, 0)]
      S, sticks = multi_tensor(
          gtab,
          mevals,
          S0=100.0,
          angles=angl,
          fractions=[50, 50],
          snr=None,
      )
      return S, sticks
  
imports: import platform
  import time
  from math import factorial
  from scipy.special import gamma
  import scipy.integrate
  import warnings
  import numpy
  from numpy.testing import assert_almost_equal, assert_array_almost_equal, assert_equal, assert_, assert_raises
  import pytest
  from dipy.core.sphere_stats import angular_similarity
  from dipy.core.subdivide_octahedron import create_unit_sphere
  from dipy.data import get_gtab_taiwan_dsi, default_sphere
  from dipy.direction.peaks import peak_directions
  from dipy.reconst.mapmri import MapmriModel, mapmri_index_matrix
  from dipy.reconst import dti, mapmri
  from dipy.reconst.odf import gfa
  from dipy.reconst.tests.test_dsi import sticks_and_ball_dummies
  from dipy.reconst.shm import sh_to_sf, descoteaux07_legacy_msg
  from dipy.sims.voxel import multi_tensor, multi_tensor_pdf, add_noise, single_tensor, cylinders_and_ball_soderman
  from dipy.testing.decorators import set_random_number_generator
label_desc: Use image node_id 2 for calling a global function with example usage: generate_signal_crossing(gtab, lambda1, lambda2, lambda3, angle2) and returns: S,  sticks