问Java BitSet，子集与交叉

EN

    BitSet bits1 = new BitSet();
    BitSet bits2 = new BitSet();
    bits1.set(0,2,true); //110
    bits2.set(1);        //010
    //010 is a SUBSET of 110
    bits1.and(bits2);    //bits1 became the result of the and operator
    if(bits1.equals(bits2))
    {
        System.out.println(bits2 + " is a subset of " + bits1);
    }
    //PRINT

    BitSet bits4 = new BitSet();
    bits4.set(0,2,true); //110
    BitSet bits3 = new BitSet();
    bits3.set(1,3,true); //011
    bits4.and(bits3);
    //011 is NOT a subset of 110
    if(bits4.equals(bits3))
    {
        System.out.println(bits4 + " is a subset of " + bits3);
    }
    //NO PRINT

    BitSet bits1 = new BitSet();
    BitSet bits2 = new BitSet();
    bits1.set(0,2,true); //110
    bits2.set(1);        //010
    //010 intersect 110, but is also a subset of 110
    System.out.println("Intersection? " + bits2.intersects(bits1));

    BitSet bits3 = new BitSet();
    bits3.set(1,3,true); //011
    //011 VS 110 intersection only
    System.out.println("Intersection? " + bits3.intersects(bits1));