public function testSetNationalIdentificationNumber() { $card = new CreditCard(); $this->assertNull($card->getNationalIdentificationNumber()); $this->assertNull($card->getSocialSecurityNumber()); $value = uniqid(); $this->assertSame($card, $card->setNationalIdentificationNumber($value)); $this->assertSame($value, $card->getNationalIdentificationNumber()); $this->assertSame($value, $card->getSocialSecurityNumber()); $this->assertSame($card, $card->setNationalIdentificationNumber(null)); $this->assertNull($card->getNationalIdentificationNumber()); $this->assertNull($card->getSocialSecurityNumber()); }