public function testAttributeAcceptsDefinedValues()
 {
     $attr = new FixedAttribute('foo', Attr::REQUIRED, ['a', 'b', 'c']);
     $attr->setValue('a');
     $this->assertSame('a', $attr->getValue());
     $attr->setValue('b');
     $this->assertSame('b', $attr->getValue());
     $attr->setValue('c');
     $this->assertSame('c', $attr->getValue());
 }
 public function testFixedAttributeWithValueObject()
 {
     $attr = new FixedAttribute('foo', Attr::REQUIRED, ['a', 'b', 'c']);
     $value = new AttributeValue('a');
     $attr->setValue($value);
     $this->assertSame('a', $attr->getValue());
 }