static Get toCheckExistenceOnly(Get get) {
    if (get.isCheckExistenceOnly()) {
      return get;
    }
    return ReflectionUtils.newInstance(get.getClass(), get).setCheckExistenceOnly(true);
  }
Create a row before the specified row and very close to the specified row.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionUtils.java