class_docstr: Given a list of classes, determines the set of classes that they inherit
  from all the way to the root "object", and then is able to generate a
  graphviz dot graph from them.
docstr: Get all of the class names involved in the graph.
code: def get_all_class_names(self) -> list[str]:
      """Get all of the class names involved in the graph."""
      return [fullname for (_, fullname, _, _) in self.class_info]
  
imports: from __future__ import annotations
  import builtins
  import hashlib
  import inspect
  import re
  from collections.abc import Iterable, Sequence
  from importlib import import_module
  from os import path
  from typing import TYPE_CHECKING, Any, cast
  from docutils import nodes
  from docutils.parsers.rst import directives
  import sphinx
  from sphinx import addnodes
  from sphinx.ext.graphviz import figure_wrapper, graphviz, render_dot_html, render_dot_latex, render_dot_texinfo
  from sphinx.util.docutils import SphinxDirective
label_desc: Use image node_id 5 for calling the InheritanceGraph obj's underlying member method code with example usage: obj.get_all_class_names() and returns: unknown