func (m Mock) PutString(key string, value string) (interface{}, error) {
	log.Info("Mock PutString:", key, value)
	m.mu.Lock()
	defer m.mu.Unlock()
	m.cache[key] = value
	return nil, nil
}
PutString stores a simple key-value pair in the mock.
package cache
import (
	"encoding/json"
	"errors"
	"fmt"
	"sync"
	"time"
	"github.com/KyleBanks/go-kit/log"
)
type Mock struct {
	mu    *sync.Mutex
	cache map[string]string
}
func NewMock() *Mock {
	return &Mock{
		mu:    &sync.Mutex{},
		cache: make(map[string]string),
	}
}