class_docstr: Not for users
code: def __iter__(self):
      return self
  
imports: import io
  import itertools
  import re
  import cloudpickle
  import numpy
  import pytensor
  import pytensor.tensor
  import pytest
  from pytensor import shared
  from pytensor.tensor.variable import TensorVariable
  import pymc
  from pymc.data import is_minibatch
  from pymc.pytensorf import GeneratorOp, floatX
label_desc: Use image node_id 2 for calling the _DataSampler obj's underlying member method code with example usage: obj.__iter__() and returns: self