public function testRequiredFiles()
{
$class = new PhpClass();
$this->assertEquals([], $class->getRequiredFiles()->toArray());
$this->assertSame($class, $class->setRequiredFiles(['foo']));
$this->assertEquals(['foo'], $class->getRequiredFiles()->toArray());
$this->assertSame($class, $class->addRequiredFile('bar'));
$this->assertEquals(['foo', 'bar'], $class->getRequiredFiles()->toArray());
}