private void digestClass() throws IOException {
long klassID = read_ID();
String name = classNames.get(klassID);
ClassData cd = new ClassData(name);
cd.addSuperClass(name);
read_U4(); // stack trace
long superKlassID = read_ID();
ClassData superCd = classDatas.get(superKlassID);
if (superCd != null) {
cd.merge(superCd);
}
read_ID(); // class loader