docs: def __get_output_filenames(self):
          """
          Set up the output filenames. If more than one file is being written out, we need appended filenames.
          :return:
          """
          # if there is only one file, use the normal filename with nothing appended.
          if len(self.noaa_data_sorted["Data"]) == 1:
              self.output_filenames.append(self.filename_txt)
  
          # if there are multiple files that need to be written out, (multiple data table pairs), then append numbers
          elif len(self.noaa_data_sorted["Data"]) > 1:
              for i in range(0, self.output_file_ct):
                  tmp_name = "{}-{}.txt".format(self.dsn, i+1)
                  self.output_filenames.append(tmp_name)
          return