code: def if_graphviz_found(app: SphinxTestApp) -> None:  # NoQA: PT004
      """
      The test will be skipped when using 'if_graphviz_found' fixture and graphviz
      dot command is not found.
      """
      graphviz_dot = getattr(app.config, "graphviz_dot", "")
      try:
          if graphviz_dot:
              # print the graphviz_dot version, to check that the binary is available
              subprocess.run(
                  [graphviz_dot, "-V"], capture_output=True, check=False
              )
              return
      except OSError:  # No such file or directory
          pass
  
      pytest.skip('graphviz "dot" is not available')
  
imports: from __future__ import annotations
  import shutil
  import subprocess
  import sys
  from collections import namedtuple
  from io import StringIO
  from typing import TYPE_CHECKING, Any, Callable
  import pytest
  from sphinx.testing.util import SphinxTestApp, SphinxTestAppWrapperForSkipBuilding
label_desc: Use image node_id 11 for calling a global function with example usage: if_graphviz_found(app) without return types