code: def language_name(self, language_code: str) -> str:
      language = super().language_name(language_code)
      if language == "ngerman" and self.use_polyglossia:
          # polyglossia calls new orthography (Neue Rechtschreibung) as
          # german (with new spelling option).
          return "german"
      elif language:
          return language
      elif language_code.startswith("zh"):
          return (
              "english"  # fallback to english (behaves like supported)
          )
      else:
          self.supported = False
          return "english"
  
file_path: sphinx/sphinx/builders/latex/util.py
imports: from __future__ import annotations
  from docutils.writers.latex2e import Babel
label_desc: Use image node_id 4 for calling the ExtBabel obj's underlying member method code with example usage: obj.language_name(language_code) and returns: str, language, str, str