docs: def create_content_type(json):
          """Create :class:`.resource.ContentType` from JSON.
  
          :param json: JSON dict.
          :return: ContentType instance.
          """
          result = ContentType(json['sys'])
  
          for field in json['fields']:
              field_id = field['id']
              del field['id']
              result.fields[field_id] = field
  
          result.name = json['name']
          result.display_field = json.get('displayField')
  
          return result