ApiPlatform\Core\Problem\Serializer\ErrorNormalizer::supportsNormalization PHP Method

    public function supportsNormalization($data, $format = null)
    {
        return self::FORMAT === $format && ($data instanceof \Exception || $data instanceof FlattenException);
    }

 public function testSupportNormalization()
 {
     $normalizer = new ErrorNormalizer();
     $this->assertTrue($normalizer->supportsNormalization(new \Exception(), ErrorNormalizer::FORMAT));
     $this->assertFalse($normalizer->supportsNormalization(new \Exception(), 'xml'));
     $this->assertFalse($normalizer->supportsNormalization(new \stdClass(), ErrorNormalizer::FORMAT));
     $this->assertTrue($normalizer->supportsNormalization(new FlattenException(), ErrorNormalizer::FORMAT));
     $this->assertFalse($normalizer->supportsNormalization(new FlattenException(), 'xml'));
     $this->assertFalse($normalizer->supportsNormalization(new \stdClass(), ErrorNormalizer::FORMAT));
 }