instance method resolve_arel_attributes

# File activerecord/lib/active_record/relation/query_methods.rb, line 2174
      def resolve_arel_attributes(attrs)
        attrs.flat_map do |attr|
          case attr
          when Arel::Predications
            attr
          when Hash
            attr.flat_map do |table, columns|
              table = table.to_s
              Array(columns).map do |column|
                predicate_builder.resolve_arel_attribute(table, column)
              end
            end
          else
            attr = attr.to_s
            if attr.include?(".")
              table, column = attr.split(".", 2)
              predicate_builder.resolve_arel_attribute(table, column)
            else
              attr
            end
          end
        end
      end