code: func newThresholdCaches(numCaches uint32) []thresholdStateCache {
  	caches := make([]thresholdStateCache, numCaches)
  	for i := 0; i < len(caches); i++ {
  		caches[i] = thresholdStateCache{
  			entries: make(map[chainhash.Hash]ThresholdState),
  		}
  	}
  	return caches
  }
docs: // newThresholdCaches returns a new array of caches to be used when calculating
  // threshold states.