func (s *MemoryStore) Del(key string) error {
	s.mutex.Lock()
	defer s.mutex.Unlock()
	delete(s.store, key)
	return nil
}
Del deletes object
package xorm
import (
	"sync"
	"github.com/go-xorm/core"
)
var _ core.CacheStore = NewMemoryStore()
type MemoryStore struct {
	store map[interface{}]interface{}
	mutex sync.RWMutex
}
func NewMemoryStore() *MemoryStore {
	return &MemoryStore{store: make(map[interface{}]interface{})}
}
func (s *MemoryStore) Put(key string, value interface{}) error {
	s.mutex.Lock()
	defer s.mutex.Unlock()
	s.store[key] = value
	return nil
}
func (s *MemoryStore) Get(key string) (interface{}, error) {
	s.mutex.RLock()
	defer s.mutex.RUnlock()
	if v, ok := s.store[key]; ok {
		return v, nil
	}
	return nil, ErrNotExist
}