Parsed test spec with 2 sessions

starting permutation: w0_fetch w1_fetch w0_commit w1_commit
step w0_fetch: 
    -- Lock then count via CTE (FOR UPDATE not allowed with aggregates).
    WITH locked AS (
        SELECT q.id
        FROM ulak.queue q
        WHERE q.status = 'pending'
          AND ((CASE WHEN q.ordering_key IS NULL THEN q.id
                     ELSE abs(hashtext(q.ordering_key))::bigint
                END) % 2) = 0
        FOR UPDATE OF q SKIP LOCKED
    )
    SELECT count(*) AS fetched FROM locked;

fetched
-------
      5
(1 row)

step w1_fetch: 
    WITH locked AS (
        SELECT q.id
        FROM ulak.queue q
        WHERE q.status = 'pending'
          AND ((CASE WHEN q.ordering_key IS NULL THEN q.id
                     ELSE abs(hashtext(q.ordering_key))::bigint
                END) % 2) = 1
        FOR UPDATE OF q SKIP LOCKED
    )
    SELECT count(*) AS fetched FROM locked;

fetched
-------
      0
(1 row)

step w0_commit: COMMIT;
step w1_commit: COMMIT;