docs: def generate_command(self):
          """ Generate a sample command
          """
          example = []
          example.append(f"{sys.argv[0]}")
          for key in sorted(list(self.spec.keys())):
              if self.spec[key]['type'] == list:
                  value = " ".join(self.spec[key].get('example', ''))
              elif self.spec[key]['type'] == dict:
                  value = f"\'{json.dumps(self.spec[key].get('example', ''))}\'"
              else:
                  value = self.spec[key].get('example', '')
              string = f"     --{key.lower()} {value}"
              example.append(string)
          print(" \\\n".join(example))