public function testIsFilledMethod() { $buyer = new Buyer(); $this->assertFalse($buyer->isFilled()); $buyer->setEmail('t'); $this->assertFalse($buyer->isFilled()); $buyer->setFirstName('t'); $this->assertFalse($buyer->isFilled()); $buyer->setLastName('t'); $this->assertTrue($buyer->isFilled()); }