docs: def parse(self, body):
          """ Invoke the JSON API spec compliant parser
  
          Order is important. Start from the request body root key
          & work your way down so exception handling is easier to
          follow.
  
          :return:
              the parsed & vetted request body
          """
  
          self._parse_top_level(body)
          self._parse_resource(body['data'])
  
          resource = body['data']
  
          if 'attributes' in resource:
              self._parse_attributes(resource['attributes'])
          if 'relationships' in resource:
              self._parse_relationships(resource['relationships'])