# File lib/polyamorous/activerecord_3_and_4.0_ruby_1.9/join_dependency.rb, line 14
    def graft_with_polymorphism(*associations)
      associations.each do |association|
        unless join_associations.detect { |a| association == a }
          if association.reflection.options[:polymorphic]
            build(
              Join.new(
                association.reflection.name,
                association.join_type,
                association.reflection.klass
                ),
              association.find_parent_in(self) || join_base,
              association.join_type
              )
          else
            build(
              association.reflection.name,
              association.find_parent_in(self) || join_base,
              association.join_type
              )
          end
        end
      end
      self
    end