Support old ver

Author: lazychaser

src/DescendantsRelation.php

@@ -62,6 +62,20 @@ public function getRelationExistenceQuery(EloquentBuilder $query, EloquentBuilde
         return $query->whereRaw("{$hash}.{$lft} between {$table}.{$lft} + 1 and {$table}.{$rgt}");
     }
 
+    /**
+     * @param EloquentBuilder $query
+     * @param EloquentBuilder $parent
+     * @param array $columns
+     *
+     * @return mixed
+     */
+    public function getRelationQuery(
+        EloquentBuilder $query, EloquentBuilder $parent,
+        $columns = [ '*' ]
+    ) {
+        return $this->getRelationExistenceQuery($query, $parent, $columns);
+    }
+
     /**
      * Get a relationship join table hash.
      *