code: def trace_generator(trace, start=0, stop=None, step=1):
      
      i = start
      stop = stop or np.inf
      size = min(trace.length(), stop)
      while i < size:
          index = slice(i, i + 1)
          yield trace.gettrace(slicing=index)[0]
          i += step
docs: Return a generator returning values from the object's trace.
  
      Ex:
      T = trace_generator(theta.trace)
      T.next()
      for t in T:...