class_docstr: Mathematics domain.
code: def process_doc(
      self,
      env: BuildEnvironment,
      docname: str,
      document: nodes.document,
  ) -> None:
      def math_node(node: Node) -> bool:
          return isinstance(node, (nodes.math, nodes.math_block))
  
      self.data["has_equations"][docname] = any(
          document.findall(math_node)
      )
  
imports: from __future__ import annotations
  from typing import TYPE_CHECKING, Any
  from docutils import nodes
  from docutils.nodes import Element, Node, make_id, system_message
  from sphinx.domains import Domain
  from sphinx.locale import __
  from sphinx.roles import XRefRole
  from sphinx.util import logging
  from sphinx.util.nodes import make_refnode
label_desc: Use image node_id 4 for calling the MathDomain obj's underlying member method code with example usage: obj.process_doc(env, docname, document) and returns: isinstance