code: def simple_init():
      start, model, moments = simple_model()
      step = Metropolis(model.value_vars, np.diag([1.0]), model=model)
      return model, start, step, moments
  
imports: from itertools import product
  import numpy
  import pytensor
  import pytensor.tensor
  from pytensor.compile.ops import as_op
  import pymc
  from pymc import Categorical, Metropolis, Model, Normal
  from pymc.pytensorf import floatX_array
label_desc: Use image node_id 6 for calling a global function with example usage: simple_init() and returns: model,  start,  step,  moments