code: def cell_language(source):
      
      if source:
          line = source[0]
          if line.startswith('%%'):
              magic = line[2:]
              if ' ' in magic:
                  lang, magic_args = magic.split(' ', 1)
              else:
                  lang = magic
                  magic_args = ''
  
              if lang in _JUPYTER_LANGUAGES:
                  source.pop(0)
                  return lang, magic_args
  
      return None, None
docs: Return cell language and language options, if any