func NewWithDB(db *leveldb.DB) *Cache {
	return &Cache{db}
}
NewWithDB returns a new Cache using the provided leveldb as underlying
storage.
package leveldbcache
import (
	"github.com/syndtr/goleveldb/leveldb"
)
type Cache struct {
	db *leveldb.DB
}
func (c *Cache) Get(key string) (resp []byte, ok bool) {
	var err error
	resp, err = c.db.Get([]byte(key), nil)
	if err != nil {
		return []byte{}, false
	}
	return resp, true
}
func (c *Cache) Set(key string, resp []byte) {
	c.db.Put([]byte(key), resp, nil)
}
func (c *Cache) Delete(key string) {
	c.db.Delete([]byte(key), nil)
}
func New(path string) (*Cache, error) {
	cache := &Cache{}
	var err error
	cache.db, err = leveldb.OpenFile(path, nil)
	if err != nil {
		return nil, err
	}
	return cache, nil
}