code: def generate_template(self, channeldir, filename, header):
          
          file_path = get_metadata_file_path(channeldir, filename)
          if not os.path.exists(file_path):
              with open(file_path, 'w') as csv_file:
                  csvwriter = csv.DictWriter(csv_file, header)
                  csvwriter.writeheader()
docs: Create empty template .csv file called `filename` as siblings of the
          directory `channeldir` with header fields specified in `header`.