initialize_relation_delegate_cache

# File activerecord/lib/active_record/relation/delegation.rb, line 13
      def initialize_relation_delegate_cache
        @relation_delegate_cache = cache = {}
        [
          ActiveRecord::Relation,
          ActiveRecord::Associations::CollectionProxy,
          ActiveRecord::AssociationRelation
        ].each do |klass|
          delegate = Class.new(klass) {
            include ClassSpecificRelation
          }
          include_relation_methods(delegate)
          mangled_name = klass.name.gsub("::", "_")
          const_set mangled_name, delegate
          private_constant mangled_name

          cache[klass] = delegate
        end
      end