code: func (r *Pool) seed(seed int64) {
  	// init a random sequence to seed all sources
  	seedRan := rand.NewSource(seed)
  	for i := uint64(0); i < r.size; i++ {
  		r.sources[i] = NewLockedRand(seedRan.Int63())
  	}
  }
docs: // seed initializes the pool using a randomized sequence with given seed.