static int indent_default = 2;

static String indent(int indent) {
  return repeat(' ', indent);
}

static String indent(int indent, String s) {
  return indent(repeat(' ', indent), s);
}

static String indent(String indent, String s) {
  return indent + replace(unnull(s), "\n", "\n" + indent);
}

static String indent(String s) {
  return indent(indent_default, s);
}

static L<S> indent(S indent, L<S> lines) {
  new L<S> l;
  if (lines != null) for (S s : lines)
    l.add(indent + s);
  ret l;
}