code: private int getArcTarget(int arc) {
      arc += ADDRESS_OFFSET;
      return (serialized[arc]           ) << 24 | 
             (serialized[arc + 1] & 0xff) << 16 | 
             (serialized[arc + 2] & 0xff) << 8  |
             (serialized[arc + 3] & 0xff);
    }
docs: Returns the address of an arc.