class_docstr: dict-like wrapper for the nested dictionaries in a SummarySubDict.
  
  Triggers self._root._callback on property changes.
class_docstr_tok: ["dict-like","wrapper","for","the","nested","dictionaries","in","a","SummarySubDict",".","Triggers","self._root._callback","on","property","changes","."]
code: def __getitem__(self, key):
      item = self._as_dict()[key]
  
      if isinstance(item, dict):
          # this nested dict needs to be wrapped:
          wrapped_item = SummarySubDict()
          object.__setattr__(wrapped_item, "_items", item)
          object.__setattr__(wrapped_item, "_parent", self)
          object.__setattr__(wrapped_item, "_parent_key", key)
  
          return wrapped_item
  
      # this item isn't a nested dict
      return item
  
imports: import abc
  import typing
  from .interface.summary_record import SummaryItem, SummaryRecord
label_desc: Use image node_id 5 for calling the SummaryDict obj's underlying member method code with example usage: obj.__getitem__(key) and returns: item, wrapped_item