package lockmgr;public class WaitObj extends DataObj{    protected Thread thread = null;        // The data members inherited are     // XObj:: protected int xid;    // TrxnObj:: protected String strData;    // TrxnObj:: protected int lockType;        WaitObj() {        super();        thread = null;    }        WaitObj(int xid, String strData, int lockType) {        super(xid, strData, lockType);        thread = null;    }        WaitObj(int xid, String strData, int lockType, Thread thread) {        super(xid, strData, lockType);        this.thread = thread;    }        public Thread getThread() {        return this.thread;    }}