code: public BatchOptions syncSlaves(int slaves, long timeout, TimeUnit unit) {
          this.syncSlaves = slaves;
          this.syncTimeout = unit.toMillis(timeout);
          return this;
      }
docs: Synchronize write operations execution within defined timeout
  across specified amount of Redis slave nodes.
  <p>
  NOTE: Redis 3.0+ required
  
  @param slaves - synchronization timeout
  @param timeout - synchronization timeout
  @param unit - synchronization timeout time unit
  @return self instance