public function test_it_can_be_constructed_with_initial_values_and_default_required_values()
 {
     $address = new Address(['building' => 'Dock Offices', 'street' => 'Surrey Quays Road']);
     $this->assertEquals('Dock Offices', $address->building());
     $this->assertFalse($address->isRequired('building'));
     $this->assertEquals('Surrey Quays Road', $address->street());
     $this->assertTrue($address->isRequired('street'));
     $this->assertEquals('', $address->city());
     $this->assertTrue($address->isRequired('city'));
     $this->assertEquals('', $address->state());
     $this->assertFalse($address->isRequired('state'));
     $this->assertEquals('', $address->postcode());
     $this->assertTrue($address->isRequired('postcode'));
     $this->assertEquals('', $address->country());
     $this->assertTrue($address->isRequired('country'));
 }