public void appendSection(@NotNull StringBuilder buf, String heading, @NotNull Collection<? extends RefElement> elements) {
    if (elements.isEmpty()) return;

    appendHeading(buf, heading);
    startList(buf);
    for (RefElement refElement : elements) {
      appendListItem(buf, refElement);
    }
    doneList(buf);
  }
public void appendSection(@NotNull StringBuilder buf, String heading, @NotNull Collection<? extends RefElement> elements)