class_docstr: - Use ROUGE-2 as [PaLM 2](https://ai.google/static/documents/palm2techreport.pdf)
  - Use Mecab tokenizer for Japanese eval
code: def doc_to_target(self, doc):
      return doc["summary"]
  
imports: import os
  import inspect
  from lm_eval.utils import rouge2_mecab
  from lm_eval.base import rf, Task
label_desc: Use image node_id 9 for calling the XLSumJa obj's underlying member method code with example usage: obj.doc_to_target(doc) and returns: doc