docs: def _parse_top_level(self, body):
          """ Ensure compliance with the spec's top-level section """
  
          link = 'jsonapi.org/format/#document-top-level'
  
          try:
              if not isinstance(body['data'], dict):
                  raise TypeError
          except (KeyError, TypeError):
              self.fail('JSON API payloads MUST be a hash at the most '
                        'top-level; rooted at a key named `data` where the '
                        'value must be a hash. Currently, we only support '
                        'JSON API payloads that comply with the single '
                        'Resource Object section.', link)
  
          if 'errors' in body:
              self.fail('JSON API payloads MUST not have both `data` & '
                        '`errors` top-level keys.', link)