code: func (p Pages) ByLanguage() Pages {
  
  	const key = "pageSort.ByLanguage"
  
  	pages, _ := spc.get(key, pageBy(languagePageSort).Sort, p)
  
  	return pages
  }
docs: // ByLanguage sorts the Pages by the language's Weight.
  //
  // Adjacent invocations on the same receiver will return a cached result.
  //
  // This may safely be executed  in parallel.