for(int j=0; j < num_fields; j++) retval[i][j]=array[i][j];
System.arraycopy(array[i], 0, retval[i], 0, num_fields);
    public int[][] getCopyOfState() {	int[][] retval=new int[num_fields][num_fields];	synchronized(array) {	    for(int i=0; i < num_fields; i++)		for(int j=0; j < num_fields; j++)		    retval[i][j]=array[i][j];	    return retval;	}    }