checks.go
func DatabasePingCheck(database *sql.DB, timeout time.Duration) Check {
	return func() error {
		ctx, cancel := context.WithTimeout(context.Background(), timeout)
		defer cancel()
		if database == nil {
			return fmt.Errorf("database is nil")
		}
		return database.PingContext(ctx)
	}
}
func DatabasePingCheck(database *sql.DB, timeout time.Duration) Check {
	return func() error {
		ctx, cancel := context.WithTimeout(context.Background(), timeout)
		defer cancel()
		if database == nil {
			return fmt.Errorf("database is nil")
		}
		return database.PingContext(ctx)
	}
}
// DatabasePingCheck returns a Check that validates connectivity to a
// database/sql.DB using Ping().