code: def test_OdfFit():
      m = SimpleOdfModel(_gtab)
      f = m.fit(None)
      odf = f.odf(_sphere)
      assert_equal(len(odf), len(_sphere.theta))
  
file_path: dipy/dipy/reconst/tests/test_odf.py
imports: import numpy
  from numpy.testing import assert_equal, assert_almost_equal, assert_
  from dipy.reconst.odf import OdfFit, OdfModel, minmax_normalize, gfa
  from dipy.core.subdivide_octahedron import create_unit_hemisphere
  from dipy.sims.voxel import multi_tensor, multi_tensor_odf
  from dipy.data import get_sphere
  from dipy.core.gradients import gradient_table, GradientTable
label_desc: Use image node_id 1 for calling a global function with example usage: test_OdfFit() without return types