class_docstr: 基础的 jittor 分类模型
class_docstr_tok: ["\u57fa\u7840\u7684","jittor","\u5206\u7c7b\u6a21\u578b"]
code: def evaluate_step(self, x, y):
      x = self(x)
      return {"pred": x, "target": y.reshape((-1,))}
  
file_path: fastNLP/tests/helpers/models/jittor_model.py
imports: from fastNLP.envs.imports import _NEED_IMPORT_JITTOR
label_desc: Use image node_id 4 for calling the JittorNormalModel_Classification_1 obj's underlying member method code with example usage: obj.evaluate_step(x, y) and returns: dict