code: def fit(self, data):
      fit = SimpleOdfFit(self, data)
      return fit
  
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 the SimpleOdfModel obj's underlying member method code with example usage: obj.fit(data) and returns: fit