public function testCatHasFluidInterfaces() { @($cat = new Cat()); $obj = $cat->setName('Gatto'); $this->assertInstanceOf('\\Animals\\Cat', $obj); $obj = $cat->setAge(3); $this->assertInstanceOf('\\Animals\\Cat', $obj); $obj = $cat->setFavoriteFood('fish'); $this->assertInstanceOf('\\Animals\\Cat', $obj); }