@ApiStatus.Experimental
  public static @NotNull MarkdownHeader createHeader(@NotNull Project project, int level, @NotNull String text) {
    final var contents = StringUtil.repeat("#", level) + " " + text;
    final var file = createFile(project, contents);
    final var element = Objects.requireNonNull(file.getFirstChild());
    assert(element instanceof MarkdownHeader);
    return (MarkdownHeader)element;
  }
@ApiStatus.Experimental
  public static @NotNull MarkdownHeader createHeader(@NotNull Project project, int level, @NotNull String text)