### Question:
RedisSequenceCounter implements SequenceCounter { @Override public Long get() { String s = valueOperations.get(counterKey); if (StringUtils.isEmpty(s)) { return null; } return Long.valueOf(s); } RedisSequenceCounter(String counterKey); @Override void set(long value); @Override Long get(); @Override long incrementAndGet(); @Override long increBy(long delta);  }### Answer:
@Test public void get() { }