public static @NotNull String readFirstAttribute(@NotNull XMLStreamReader reader, @NotNull String attributeName) throws XMLStreamException {
    String name = reader.getAttributeLocalName(0);
    if (!attributeName.equals(name)) {
      throw new XMLStreamException("incorrect first attribute: " + attributeName + " expected but " + name + " found");
    }
    return reader.getAttributeValue(0);
  }
public static @NotNull String readFirstAttribute(@NotNull XMLStreamReader reader, @NotNull String attributeName)