class_docstr: A subclass of :class:`Sphinx` that runs on the test root, with some
  better default values for the initialization parameters.
code: def build(
      self, force_all: bool = False, filenames: list[str] | None = None
  ) -> None:
      self.env._pickled_doctree_cache.clear()
      super().build(force_all, filenames)
  
imports: from __future__ import annotations
  import contextlib
  import os
  import re
  import sys
  import warnings
  from typing import IO, TYPE_CHECKING, Any
  from xml.etree import ElementTree
  from docutils import nodes
  from sphinx import application
label_desc: Use image node_id 4 for calling the SphinxTestApp obj's underlying member method code with example usage: obj.build(force_all, filenames) without return types