code: public void testColumnCompare() throws Exception {
    final byte[] a=Bytes.toBytes("aaa");
    byte[] family1=Bytes.toBytes("abc");
    byte[] qualifier1=Bytes.toBytes("def");
    byte[] family2=Bytes.toBytes("abcd");
    byte[] qualifier2=Bytes.toBytes("ef");
    KeyValue aaa=new KeyValue(a,family1,qualifier1,0L,Type.Put,a);
    assertFalse(aaa.matchingColumn(family2,qualifier2));
    assertTrue(aaa.matchingColumn(family1,qualifier1));
    aaa=new KeyValue(a,family2,qualifier2,0L,Type.Put,a);
    assertFalse(aaa.matchingColumn(family1,qualifier1));
    assertTrue(aaa.matchingColumn(family2,qualifier2));
    byte[] nullQualifier=new byte[0];
    aaa=new KeyValue(a,family1,nullQualifier,0L,Type.Put,a);
    assertTrue(aaa.matchingColumn(family1,null));
    assertFalse(aaa.matchingColumn(family2,qualifier2));
  }
  