svoid tok_beginPeriod(LS tok) {
  for (i : jfind_all_reversed(tok, "begin.",
    (_tok, nIdx) -> _get(tok, startsWithSpaceEtc(nIdx+4)))) {
    int iClosing = tok_findEndOfBlock(tok, i)-1;
    tokPrepend_reTok(tok, iClosing, "}\n");
    tokReplace_reTok(tok, i, i+3, "run {");
  }
}