# File lib/faster_csv.rb, line 234
      def <<(arg)
        if arg.is_a?(Array) and arg.size == 2  # appending a header and name
          @row << arg
        elsif arg.is_a?(Hash)                  # append header and name pairs
          arg.each { |pair| @row << pair }
        else                                   # append field value
          @row << [nil, arg]
        end

        self  # for chaining
      end