protected void scanTestNull(Table ht, byte[] row, byte[] family, byte[] value,
    boolean isReversedScan) throws Exception {

    Scan scan = new Scan();
    scan.setReversed(isReversedScan);
    scan.addColumn(family, null);
    Result result = getSingleScanResult(ht, scan);
    assertSingleResult(result, row, family, HConstants.EMPTY_BYTE_ARRAY, value);

    scan = new Scan();
    scan.setReversed(isReversedScan);
    scan.addColumn(family, HConstants.EMPTY_BYTE_ARRAY);
    result = getSingleScanResult(ht, scan);
    assertSingleResult(result, row, family, HConstants.EMPTY_BYTE_ARRAY, value);

    scan = new Scan();
    scan.setReversed(isReversedScan);
    scan.addFamily(family);
    result = getSingleScanResult(ht, scan);
    assertSingleResult(result, row, family, HConstants.EMPTY_BYTE_ARRAY, value);

    scan = new Scan();
    scan.setReversed(isReversedScan);
    result = getSingleScanResult(ht, scan);
    assertSingleResult(result, row, family, HConstants.EMPTY_BYTE_ARRAY, value);

  }
Validate that result contains two specified keys, exactly. It is assumed key A sorts before key
B.
hbase-server/src/test/java/org/apache/hadoop/hbase/client/FromClientSideBase.java