class_docstr: iterator dataset initailizer 
class_docstr_tok: ["iterator","dataset","initailizer"]
code: def begin(self):
      self._initializer = self._iterator.initializer
  
imports: import delta.compat
  from bisect import bisect_right
  from absl import logging
label_desc: Use image node_id 2 for calling the DatasetInitializerHook obj's underlying member method code with example usage: obj.begin() without return types