minor fixes to serialization

Author: Mantas Marcinkevicius

Mapping/Converter.php

@@ -28,9 +28,7 @@ public function addClassMetadata(string $class, array $metadata): void
     public function convertArrayToDocument(string $namespace, array $raw)
     {
         if (!isset($this->propertyMetadata[$namespace])) {
-            echo json_encode($raw, JSON_PRETTY_PRINT);
-
-            return [];
+            throw new \Exception("Cannot convert array to object of class `$class`.");
         }
 
         return $this->denormalize($raw, $namespace);

Mapping/DocumentParser.php

@@ -287,7 +287,7 @@ private function guessGetter(\ReflectionClass $class, $name): string
         }
 
         if ($class->hasMethod('is' . ucfirst($name))) {
-            return 'get' . ucfirst($name);
+            return 'is' . ucfirst($name);
         }
 
         throw new \Exception("Could not determine a getter for `$name` of class `{$class->getNamespaceName()}`");