# File lib/sax-machine/sax_document.rb, line 124
    def create_attr(real_name, &block)
      attr_reader(real_name) unless method_defined?(real_name)

      if !method_defined?("#{real_name}=")
        if block_given?
          define_method("#{real_name}=") do |value|
            instance_variable_set("@#{real_name}", instance_exec(value, &block))
          end
        else
          attr_writer(real_name)
        end
      end
    end