class_docstr: Domain for citations.
class_docstr_tok: ["Domain","for","citations","."]
code: def citations(self) -> dict[str, tuple[str, str, int]]:
      return self.data.setdefault("citations", {})
  
imports: from __future__ import annotations
  from typing import TYPE_CHECKING, Any, cast
  from docutils import nodes
  from sphinx.addnodes import pending_xref
  from sphinx.domains import Domain
  from sphinx.locale import __
  from sphinx.transforms import SphinxTransform
  from sphinx.util import logging
  from sphinx.util.nodes import copy_source_info, make_refnode
label_desc: Use image node_id 1 for calling the CitationDomain obj's underlying member method code with example usage: obj.citations() and returns: self