/**
     * Test the cron scheduling method
     */
    public function test_eval_cron_field() {
        $testclass = new \core\task\scheduled_test_task();

        $this->assertEquals(20, count($testclass->eval_cron_field('*/3', 0, 59)));
        $this->assertEquals(31, count($testclass->eval_cron_field('1,*/2', 0, 59)));
        $this->assertEquals(15, count($testclass->eval_cron_field('1-10,5-15', 0, 59)));
        $this->assertEquals(13, count($testclass->eval_cron_field('1-10,5-15/2', 0, 59)));
        $this->assertEquals(3, count($testclass->eval_cron_field('1,2,3,1,2,3', 0, 59)));
        $this->assertEquals(1, count($testclass->eval_cron_field('-1,10,80', 0, 59)));
    }