app/models/chapter.rb in mumuki-domain-7.1.0 vs app/models/chapter.rb in mumuki-domain-7.2.0

@@ -1,29 +1,29 @@
 class Chapter < ApplicationRecord
   include WithStats
   include WithNumber
 
+  include SiblingsNavigation
+  include TerminalNavigation
+
   include FriendlyName
 
   include TopicContainer
 
   belongs_to :book, optional: true
-  belongs_to :topic
 
   has_many :exercises, through: :topic
 
-  include SiblingsNavigation
-  include TerminalNavigation
 
   def used_in?(organization)
     organization.book == self.book
   end
 
-  def pending_siblings_for(user)
-    book.pending_chapters(user)
-  end
-
   def index_usage!(organization = Organization.current)
     organization.index_usage_of! topic, self
     lessons.each { |lesson| lesson.index_usage! organization }
+  end
+
+  def structural_parent
+    book
   end
 end