WorklistPatient::afterValidate PHP Method

    public function afterValidate()
    {
        if ($this->worklist->scheduled) {
            if (empty($this->when)) {
                $this->addError('when', $this->getAttributeLabel('when') . ' is required when the Worklist is scheduled.');
            }
        } else {
            if (!empty($this->when)) {
                $this->addError('when', $this->getAttributeLabel('when') . ' cannot be set when the Worklist not scheduled.');
            }
        }
        parent::afterValidate();
    }

 public function test_afterValidate_for_unscheduled_worklist()
 {
     $wl = ComponentStubGenerator::generate('Worklist', array('scheduled' => false));
     $wp = new WorklistPatient();
     $wp->worklist = $wl;
     $wp->when = (new DateTime())->format('Y-m-d H:i:s');
     $wp->afterValidate();
     $this->assertTrue($wp->hasErrors());
     $this->assertArrayHasKey('when', $wp->getErrors());
 }