public function testValuesWithNullFilename()
 {
     $source = '<?php echo "Hello world";';
     $file = null;
     $locatedSource = new LocatedSource($source, $file);
     $this->assertSame($source, $locatedSource->getSource());
     $this->assertNull($locatedSource->getFileName());
 }
 /**
  * @return string|null
  */
 public function getFileName()
 {
     return $this->locatedSource->getFileName();
 }