func (il *internalLocker) Lock(ctx context.Context) error {
	il.locks.Lock(il.key)
	return nil
}
Lock locks the mutex.
package memory
import (
	"context"
	"github.com/moby/locker"
	"github.com/yorkie-team/yorkie/internal/log"
)
type internalLocker struct {
	key   string
	locks *locker.Locker
}