src/Normalizer/FieldItemNormalizer.php | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/Normalizer/FieldItemNormalizer.php b/src/Normalizer/FieldItemNormalizer.php
index e61a927..00b0b58 100644
--- a/src/Normalizer/FieldItemNormalizer.php
+++ b/src/Normalizer/FieldItemNormalizer.php
@@ -31,6 +31,8 @@ class FieldItemNormalizer extends NormalizerBase {
   public function normalize($field_item, $format = NULL, array $context = array()) {
     /** @var \Drupal\Core\TypedData\TypedDataInterface $property */
     $values = [];
+    // We normalize each individual property, so each can do their own casting,
+    // if needed.
     foreach ($field_item as $property_name => $property) {
       $values[$property_name] = $this->serializer->normalize($property, $format, $context);
     }