class_docstr: A logging filter designed to record missing reference warning messages
  for use by this extension
code: def _record_reference(self, record):
      if not (
          getattr(record, "type", "") == "ref"
          and isinstance(getattr(record, "location", None), nodes.Node)
      ):
          return
  
      if not hasattr(self.app.env, "missing_references_warnings"):
          self.app.env.missing_references_warnings = defaultdict(set)
  
      record_missing_reference(
          self.app,
          self.app.env.missing_references_warnings,
          record.location,
      )
  
imports: from collections import defaultdict
  import json
  import logging
  from pathlib import Path
  from docutils.utils import get_source_line
  from docutils import nodes
  from sphinx.util import logging
  import matplotlib
label_desc: Use image node_id 2 for calling the MissingReferenceFilter obj's underlying member method code with example usage: obj._record_reference(record) without return types