--- /dev/null
+<?php
+
+namespace Drupal\serialization\EntityResolver;
+
+use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+
+/**
+ * Interface for extracting UUID from entity reference data when denormalizing.
+ */
+interface UuidReferenceInterface extends NormalizerInterface {
+
+ /**
+ * Get the uuid from the data array.
+ *
+ * @param array $data
+ * The data, as was passed into the Normalizer.
+ *
+ * @return string
+ * A UUID.
+ */
+ public function getUuid($data);
+
+}