static <A extends Iterable> A pnl(S prefix, A l) {
  printNumberedLines(prefix, l);
  ret l;
}

static <A extends Iterable> A pnl(A l) {
  printNumberedLines(l);
  ret l;
}

static <A extends Map> A pnl(A map) {
  printNumberedLines(map);
  ret map;
}

static <A extends Map> A pnl(S prefix, A map) {
  printNumberedLines(prefix, map);
  ret map;
}

static <A> A[] pnl(A[] a) {
  printNumberedLines(a);
  ret a;
}

sS pnl(S s) {
  printNumberedLines(lines(s));
  ret s;
}