# File lib/active_resource/base.rb, line 321
      def schema(&block)
        if block_given?
          schema_definition = Schema.new
          schema_definition.instance_eval(&block)

          # skip out if we didn't define anything
          return unless schema_definition.attrs.present?

          @schema ||= {}.with_indifferent_access
          @known_attributes ||= []

          schema_definition.attrs.each do |k,v|
            @schema[k] = v
            @known_attributes << k
          end

          schema
        else
          @schema ||= nil
        end
      end