code: def to_s(format = 'dd/mm/yyyy')
        SUPPORTED_FIELDS.collect do |k,v|
          next unless current = instance_variable_get("@#{k}")
          field = v.keys.first
          case current.class.to_s
          when "Time", "Date", "DateTime"
            "#{field}#{DateFormat.new(format).format(current)}"
          when "Float"
            "#{field}#{'%.2f'%current}"
          when "String"
            current.split("\n").collect {|x| "#{field}#{x}" }
          else
            "#{field}#{current}"
          end
        end.concat(@splits.collect{|s| s.to_s}).flatten.compact.join("\n")
      end
docs: Returns a representation of the transaction as it
   would appear in a qif file.