code: func (p Pages) ByTitle() Pages {
  
  	const key = "pageSort.ByTitle"
  
  	title := func(p1, p2 Page) bool {
  		return p1.Title() < p2.Title()
  	}
  
  	pages, _ := spc.get(key, pageBy(title).Sort, p)
  	return pages
  }
docs: // ByTitle sorts the Pages by title and returns a copy.
  //
  // Adjacent invocations on the same receiver will return a cached result.
  //
  // This may safely be executed  in parallel.