}
        }

        instr.close()
    }

    @Test
    void readBlocksUntilInputStreamIsClosed() {
        clockTick(1).hasParticipants(3)
        clockTick(2).hasParticipants(3)

        def source = stream()
        source.onRead { buffer, pos, count ->
            syncAt(1)
            syncAt(2)
            return count
        }

        boolean waitUntil(Date expiry);

        boolean isCurrentThread();

        void waitUntilBlocked();
    }

    public interface ClockTick {
        ClockTick hasParticipants(int count);
    }

    private static class ClockTickImpl implements ClockTick {
        private final int number;
        private int participants;

        private ClockTickImpl(int number) {