private static @Nullable String getChildAttribute(@NotNull Element parent, @NotNull String childName, @NotNull String attributeName) {
    Element child = parent.getChild(childName);
    if (child == null) {
      return null;
    }
    return child.getAttributeValue(attributeName);
  }
private static @Nullable String getChildAttribute(@NotNull Element parent, @NotNull String childName, @NotNull String attributeName)