initialize_relation_delegate_cache

# File activerecord/lib/active_record/relation/delegation.rb, line 12
      def initialize_relation_delegate_cache # :nodoc:
        @relation_delegate_cache = cache = {}
        [
          ActiveRecord::Relation,
          ActiveRecord::Associations::CollectionProxy,
          ActiveRecord::AssociationRelation
        ].each do |klass|
          delegate = Class.new(klass) {
            include ClassSpecificRelation
          }
          const_set klass.name.gsub('::', '_'), delegate
          cache[klass] = delegate
        end
      end