JBZoo\PHPUnit\CalcTest::testFunction PHP Method

    public function testFunction()
    {
        $val = val('100 eur');
        $val->customFunc(function ($value) {
            $value->multiply(6.5)->add('55%')->negative('55%');
        })->customFunc(function ($value) {
            $value->add(array(50, 'usd'))->convert('byr');
        });
        is('20650000 byr', $val->dump(false));
    }