protected void verifyOneScanAcrossSnapshot2(KeyValue kv1, KeyValue kv2) throws IOException {
    List<KeyValueScanner> memstorescanners = this.memstore.getScanners(mvcc.getReadPoint());
    assertEquals(1, memstorescanners.size());
    final KeyValueScanner scanner0 = memstorescanners.get(0);
    scanner0.seek(KeyValueUtil.createFirstOnRow(HConstants.EMPTY_START_ROW));
    Cell n0 = scanner0.next();
    Cell n1 = scanner0.next();
    assertTrue(kv1.equals(n0));
    assertTrue(kv2.equals(n1));
    assertNull(scanner0.next());
  }
A simple test which verifies the 3 possible states when scanning across snapshot.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestDefaultMemStore.java