Example in "42.8. Transaction Management" doesn't work for PostgreSQL v 12.7

--run before:

--create table test1(a int);

CREATE PROCEDURE transaction_test1()

LANGUAGE plpgsql

AS $$

BEGIN

    FOR i IN 0..9 LOOP

        INSERT INTO test1 (a) VALUES (i);

        IF i % 2 = 0 THEN

            COMMIT;

        ELSE

            ROLLBACK;

        END IF;

    END LOOP;

END;

$$;

ERROR: invalid transaction termination

CONTEXT: PL/pgSQL function transaction_test1() line 6 at COMMIT

SQL state: 2D000