func CacheUnloads() int64 {
	return cacheUnloadCounter.Count()
}
CacheUnloads retrieves a global counter measuring the number of cache unloads
the trie did since process startup. This isn't useful for anything apart from
trie debugging purposes.
package trie
import (
	"bytes"
	"fmt"
	"github.com/dappledger/AnnChain/eth/common"
	"github.com/dappledger/AnnChain/eth/crypto"
	"github.com/dappledger/AnnChain/eth/log"
	"github.com/dappledger/AnnChain/eth/metrics"
)
var (
	emptyRoot = common.HexToHash("56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421")
	emptyState = crypto.Keccak256Hash(nil)
)
var (
	cacheMissCounter   = metrics.NewRegisteredCounter("trie/cachemiss", nil)
	cacheUnloadCounter = metrics.NewRegisteredCounter("trie/cacheunload", nil)
)
func CacheMisses() int64 {
	return cacheMissCounter.Count()
}