refactored code

lib/gitlab/import_export/project_tree_restorer.rb

@@ -56,8 +56,7 @@ module Gitlab
           if relation.is_a?(Hash)
             create_sub_relations(relation, @tree_hash)
           elsif @tree_hash[relation.to_s].present?
-            relation_key = relation.is_a?(Hash) ? relation.keys.first : relation
-            save_relation_hash(@tree_hash[relation_key.to_s], relation_key)
+            save_relation_hash(@tree_hash[relation.to_s], relation)
           end
         end
 
@@ -101,7 +100,7 @@ module Gitlab
       # issue, finds any subrelations such as notes, creates them and assign them back to the hash
       #
       # Recursively calls this method if the sub-relation is a hash containing more sub-relations
-      def create_sub_relations(relation, tree_hash, save = true)
+      def create_sub_relations(relation, tree_hash, save: true)
         relation_key = relation.keys.first.to_s
         return if tree_hash[relation_key].blank?
 
@@ -133,7 +132,7 @@ module Gitlab
           # We just use author to get the user ID, do not attempt to create an instance.
           next if sub_relation == :author
 
-          create_sub_relations(sub_relation, relation_item, false) if sub_relation.is_a?(Hash)
+          create_sub_relations(sub_relation, relation_item, save: false) if sub_relation.is_a?(Hash)
 
           relation_hash, sub_relation = assign_relation_hash(relation_item, sub_relation)
           relation_item[sub_relation.to_s] = create_relation(sub_relation, relation_hash) unless relation_hash.blank?