polymorphic_base_class_from_value

# File activerecord/lib/active_record/relation/predicate_builder/association_query_handler.rb, line 66
      def polymorphic_base_class_from_value
        case value
        when Relation
          value.klass.base_class
        when Array
          val = value.compact.first
          val.class.base_class if val.is_a?(Base)
        when Base
          value.class.base_class
        end
      end