static LS gazelle_expandThey(final GazelleTree tree) {
  if (!cic(tree.line, "they")) null;
  LS replacements = uniquify(map afterEquals_trim(collect line(gazelle_searchTreeUpwardsForDefinitions("they", tree))));
  if (empty(replacements)) null;
  ret map(replacements, func(S s) -> S {
    jreplaceIC(tree.line, "they", optCurly(s))
  });
}