Plum\Plum\WorkflowTest::addFilterConvertsCallbackIntoCallbackConverter PHP Метод

    public function addFilterConvertsCallbackIntoCallbackConverter()
    {
        $this->workflow->addFilter(function ($item) {
            return $item;
        });
        $this->assertInstanceOf('Plum\\Plum\\Filter\\FilterInterface', $this->workflow->getFilters()[0]->getFilter());
    }