graft

# File activerecord/lib/active_record/associations/join_dependency.rb, line 21
      def graft(*associations)
        associations.each do |association|
          join_associations.detect {|a| association == a} ||
            build(association.reflection.name, association.find_parent_in(self) || join_base, association.join_type)
        end
        self
      end