code: def _get_param_names(self):
          
          template = Template(self.yaml_string)
          names = ['yaml_string']  # always include the template
          for match in re.finditer(template.pattern, template.template):
              name = match.group('named') or match.group('braced')
              assert name is not None
              names.append(name)
          return names
docs: Get mappable parameters from YAML.