class_docstr: Dictionary wrapper that prevents modifications to the dictionary 
class_docstr_tok: ["Dictionary","wrapper","that","prevents","modifications","to","the","dictionary"]
code: def _nested_callback(self, prefix, key_value):
      return self._set_callback(
          (
              prefix + "." + key_value[0],
              key_value[1],
          )
      )
  
imports: import itertools
  import json
  from copy import copy
  from logging import getLogger
  import six
  import yaml
label_desc: Use image node_id 5 for calling the ProxyDictPreWrite obj's underlying member method code with example usage: obj._nested_callback(prefix, key_value) and returns: self