class_docstr: Stores some state that persists between recursions into the element tree
code: def __getitem__(self, key: int) -> ElementState:
      return self._element_diagram_states[key]
  
imports: import railroad
  import pyparsing
  import typing
  from typing import List, NamedTuple, Generic, TypeVar, Dict, Callable, Set, Iterable
  from jinja2 import Template
  from io import StringIO
  import inspect
label_desc: Use image node_id 3 for calling the ConverterState obj's underlying member method code with example usage: obj.__getitem__(key) and returns: self