public function testCheckDigit() { $this->assertEquals(8, Converter::calculateCheckDigit(14080, 12712721)); $this->assertEquals(1, converter::calculateCheckDigit(10000, 81111111)); $this->assertEquals(9, converter::calculateCheckDigit(10000, 80000001)); $this->assertEquals(5, converter::calculateCheckDigit(16150, 12233411)); $this->assertEquals(7, converter::calculateCheckDigit(10001, 10001)); }