def validate_export_format(format)
        unless MakeExportable.exportable_formats.keys.include?(format.to_sym)
          raise MakeExportable::FormatNotFound.new("#{format} is not a supported format.")
        end
        unless exportable_options[:formats].include?(format.to_sym)
          raise MakeExportable::FormatNotFound.new("#{format} format is not allowed on this class.")
        end
      end
def validate_export_format(format)
        unless MakeExportable.exportable_formats.keys.include?(format.to_sym)
          raise MakeExportable::FormatNotFound.new("#{format} is not a supported format.")
        end
        unless exportable_options[:formats].include?(format.to_sym)
          raise MakeExportable::FormatNotFound.new("#{format} format is not allowed on this class.")
        end
      end
<tt>validate_export_format</tt> ensures that the requested export format is valid.