code: def fetch(self):
          
          if self.data.type == self._manager.FOLDER_TYPE:
              raise YagocdException("Can't fetch folder <{}>, only file!".format(self._path))
  
          response = self._session.get(self.data.url)
          return response.content
docs: Method for getting artifact's content.
          Could only be applicable for file type.
  
          :return: content of the artifact.