Merge pull request #4 from mrsuh/dev

$parent_properties

Author: mrsuh

src/Document/Document.php

@@ -18,9 +18,9 @@ public function getId()
      * @param $id
      * @return $this
      */
-    public function setId(string $id)
+    public function setId($id)
     {
-        $this->id = $id;
+        $this->id = (string)$id;
 
         return $this;
     }

src/DocumentMapper/DataMapper.php

@@ -133,7 +133,8 @@ private function mapObj(string $class_name, array $data)
     {
         $obj     = $this->instantiator->instantiate($class_name);
         $reflect = new \ReflectionClass($obj);
-        $properties = array_merge($reflect->getProperties(), $reflect->getParentClass()->getProperties());
+        $parent_properties = null !== $reflect->getParentClass() ? $reflect->getParentClass()->getProperties() : [];
+        $properties = array_merge($reflect->getProperties(), $parent_properties);
 
         foreach($properties  as $prop) {
 
@@ -186,7 +187,8 @@ private function objToArray(Document $obj)
     {
         $data    = [];
         $reflect = new \ReflectionClass($obj);
-        $properties = array_merge($reflect->getProperties(), $reflect->getParentClass()->getProperties());
+        $parent_properties = null !== $reflect->getParentClass() ? $reflect->getParentClass()->getProperties() : [];
+        $properties = array_merge($reflect->getProperties(), $parent_properties);
 
         foreach ($properties as $prop) {