lookup_cast_type_from_join_dependencies

# File activerecord/lib/active_record/relation/calculations.rb, line 574
      def lookup_cast_type_from_join_dependencies(name, join_dependencies = build_join_dependencies)
        each_join_dependencies(join_dependencies) do |join|
          type = join.base_klass.attribute_types.fetch(name, nil)
          return type if type
        end
        nil
      end