svoid test_indentedStringsToForest() {
  L<Tree<S>> forest = print(indentedStringsToForest(ll("  bla", "    hello", "  blu")));
  assertEqualsVerbose(2, l(forest));
  Tree<S> tree = forest.get(0);
  assertEqualsVerbose("bla", tree!);
  assertEqualsVerbose(1, l(tree.children));
  tree = tree.children.get(0);
  assertEqualsVerbose("hello", tree!);
  assertEqualsVerbose(0, l(tree.children));
  tree = forest.get(1);
  assertEqualsVerbose("blu", tree!);
  assertEqualsVerbose(0, l(tree.children));
}