code: def sleep_study():
      "Model with common and group specific effects"
      data = bmb.load_data("sleepstudy")
      model = bmb.Model("Reaction ~ 1 + Days + (Days | Subject)", data)
      idata = model.fit(tune=500, draws=500, random_seed=1234)
      return model, idata
  
imports: from os.path import dirname, join
  import numpy
  import pandas
  import matplotlib.pyplot
  import pytest
  import bambi
  from bambi.interpret import plot_comparisons, plot_predictions, plot_slopes
label_desc: Use image node_id 2 for calling a global function with example usage: sleep_study() and returns: model,  idata