private static void writeClasspathEntry(IonWriter writer, ClasspathEntryModel entry) throws IOException {
    writer.stepIn(IonType.STRUCT);
    writeStrings(writer, "classes", entry.getClasses());
    writeStrings(writer, "sources", entry.getSources());
    writeStrings(writer, "javadoc", entry.getJavadoc());
    writer.stepOut();
  }
private static void writeClasspathEntry(IonWriter writer, ClasspathEntryModel entry)