docstr: 聚集结果，并根据 method 计算后，返回结果
docstr_tok: ["\u805a\u96c6\u7ed3\u679c\uff0c\u5e76\u6839\u636e","method","\u8ba1\u7b97\u540e\uff0c\u8fd4\u56de\u7ed3\u679c"]
code: def aggregate(self, tensor, method: str):
      """
      聚集结果，并根据 method 计算后，返回结果
      """
      return tensor
  
file_path: fastNLP/fastNLP/core/metrics/backend/jittor_backend/backend.py
imports: import numpy
  from fastNLP.envs.imports import _NEED_IMPORT_JITTOR
  from fastNLP.core.metrics.backend import Backend
label_desc: Use image node_id 2 for calling the JittorBackend obj's underlying member method code with example usage: obj.aggregate(tensor, method) and returns: tensor