minor #17429 [Serializer] Minor: fix CS and PHPDoc (dunglas)

This PR was squashed before being merged into the 2.7 branch (closes #17429).

Discussion
----------

[Serializer] Minor: fix CS and PHPDoc

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | n/a

Commits
-------

ff568dc [Serializer] Minor: fix CS and PHPDoc

src/Symfony/Component/Serializer/Mapping/Factory/ClassMetadataFactory.php

@@ -27,10 +27,12 @@ class ClassMetadataFactory implements ClassMetadataFactoryInterface
      * @var LoaderInterface
      */
     private $loader;
+
     /**
      * @var Cache
      */
     private $cache;
+
     /**
      * @var array
      */

src/Symfony/Component/Serializer/Mapping/Loader/YamlFileLoader.php

@@ -65,6 +65,7 @@ class YamlFileLoader extends FileLoader
 
             if (isset($yaml['attributes']) && is_array($yaml['attributes'])) {
                 $attributesMetadata = $classMetadata->getAttributesMetadata();
+
                 foreach ($yaml['attributes'] as $attribute => $data) {
                     if (isset($attributesMetadata[$attribute])) {
                         $attributeMetadata = $attributesMetadata[$attribute];

src/Symfony/Component/Serializer/NameConverter/CamelCaseToSnakeCaseNameConverter.php

@@ -22,6 +22,7 @@ class CamelCaseToSnakeCaseNameConverter implements NameConverterInterface
      * @var array|null
      */
     private $attributes;
+
     /**
      * @var bool
      */

src/Symfony/Component/Serializer/Normalizer/AbstractNormalizer.php

@@ -35,26 +35,32 @@ abstract class AbstractNormalizer extends SerializerAwareNormalizer implements N
      * @var int
      */
     protected $circularReferenceLimit = 1;
+
     /**
      * @var callable
      */
     protected $circularReferenceHandler;
+
     /**
      * @var ClassMetadataFactoryInterface|null
      */
     protected $classMetadataFactory;
+
     /**
      * @var NameConverterInterface|null
      */
     protected $nameConverter;
+
     /**
      * @var array
      */
     protected $callbacks = array();
+
     /**
      * @var array
      */
     protected $ignoredAttributes = array();
+
     /**
      * @var array
      */

src/Symfony/Component/Serializer/Serializer.php

@@ -41,18 +41,22 @@ class Serializer implements SerializerInterface, NormalizerInterface, Denormaliz
      * @var Encoder\ChainEncoder
      */
     protected $encoder;
+
     /**
      * @var Encoder\ChainDecoder
      */
     protected $decoder;
+
     /**
      * @var array
      */
     protected $normalizers = array();
+
     /**
      * @var array
      */
     protected $normalizerCache = array();
+
     /**
      * @var array
      */
@@ -247,8 +251,10 @@ class Serializer implements SerializerInterface, NormalizerInterface, Denormaliz
         }
 
         foreach ($this->normalizers as $normalizer) {
-            if ($normalizer instanceof DenormalizerInterface
-                && $normalizer->supportsDenormalization($data, $class, $format)) {
+            if (
+                $normalizer instanceof DenormalizerInterface &&
+                $normalizer->supportsDenormalization($data, $class, $format)
+            ) {
                 return $normalizer->denormalize($data, $class, $format, $context);
             }
         }