static Pair<SS> textsAndTitlesMapFromLCXZSnippet(S snippetID) {
  LineCompReader lcr = new(xzInputStream(loadLibrary(snippetID)));
  Set<S> snippetIDs = mapToTreeSet(s -> fsI(parseFirstInt(s)), startingWithDigit(lcr.versions()));
  SS titles = mapKeys fsI(parseColonProperties(lcr.textForVersion("titles.text")));
  SS texts = new ValueOnDemandMap<S>(snippetIDs, s -> lcr.textForVersion(psI(s) + ".text"));
  ret pair(texts, titles);
}