Use the newRelatedThroughInstance method to prepare the through par…

…ents (#154)

* use `newRelatedThroughInstance` method

* check if method exists to support older versions

src/HasRelationships.php

@@ -102,7 +102,9 @@ protected function hasOneOrManyDeepThroughParents(array $through)
             $segments = preg_split('/\s+as\s+/i', $class);
 
             $instance = Str::contains($segments[0], '\\')
-                ? new $segments[0]()
+                ? (method_exists($this, 'newRelatedThroughInstance')
+                    ? $this->newRelatedThroughInstance($segments[0])
+                    : new $segments[0]())
                 : (new Pivot())->setTable($segments[0]);
 
             if (isset($segments[1])) {