class_docstr: Add the domain name of the parent node as a class in each desc_signature node.
class_docstr_tok: ["Add","the","domain","name","of","the","parent","node","as","a","class","in","each","desc_signature","node","."]
code: def run(self, **kwargs: Any) -> None:
      for node in self.document.findall(addnodes.desc_signature):
          if node.parent.get("domain"):
              node["classes"].append(node.parent["domain"])
  
imports: from __future__ import annotations
  import re
  from typing import TYPE_CHECKING, Any, cast
  from docutils import nodes
  from docutils.nodes import Element, Node
  from sphinx import addnodes
  from sphinx.errors import NoUri
  from sphinx.locale import __
  from sphinx.transforms import SphinxTransform
  from sphinx.util import logging
  from sphinx.util.docutils import SphinxTranslator
  from sphinx.util.nodes import find_pending_xref_condition, process_only_nodes
label_desc: Use image node_id 1 for calling the PropagateDescDomain obj's underlying member method code with example usage: obj.run() without return types