"strings"
	"sync"
	"sync/atomic"
	"testing"
	"time"
)

func init() {
	type dbConn struct {
		db *DB
		c  *driverConn
	}
	freedFrom := make(map[dbConn]string)
	var mu sync.Mutex
	getFreedFrom := func(c dbConn) string {
		mu.Lock()
		defer mu.Unlock()
		return freedFrom[c]
	}
	setFreedFrom := func(c dbConn, s string) {
		mu.Lock()
		defer mu.Unlock()
		freedFrom[c] = s
	}