class_docstr: **Quora matching** 任务的数据集 **Loader**。
  支持读取的文件中的内容应该有以下的形式：以制表符分隔，且前三列一定分别为 **label** ， **句子1** ， **句子2** 。
  
  Example::
  
      1       How do I get funding for my web based startup idea ?    How do I get seed funding pre product ? 327970
      0       Is honey a viable alternative to sugar for diabetics ?  How would you compare the United States ' euthanasia laws to Denmark ?  90348
      ...
  
  读取的 :class:`~fastNLP.core.DataSet` 将具备以下的数据结构：
  
  .. csv-table::
      :header: "raw_words1", "raw_words2", "target"
  
      "How do I get funding for my web based...", "How do I get seed funding...","1"
      "Is honey a viable alternative ...", "How would you compare the United...","0"
      "...","...","..."
docstr: 由于版权限制，不能提供自动下载功能。可参考
  
  https://www.kaggle.com/c/quora-question-pairs/data
  
  :return:
docstr_tok: ["\u7531\u4e8e\u7248\u6743\u9650\u5236\uff0c\u4e0d\u80fd\u63d0\u4f9b\u81ea\u52a8\u4e0b\u8f7d\u529f\u80fd\u3002\u53ef\u53c2\u8003","https",":","\/\/www.kaggle.com\/c\/quora-question-pairs\/data",":","return",":"]
code: def download(self):
      r"""
      由于版权限制，不能提供自动下载功能。可参考
  
      https://www.kaggle.com/c/quora-question-pairs/data
  
      :return:
      """
      r"""
          自动下载数据集。
  
          :return: 数据集目录地址
          """
      raise RuntimeError("Quora cannot be downloaded automatically.")
  
imports: import os
  from typing import Union, Dict
  from .csv import CSVLoader
  from .json import JsonLoader
  from .loader import Loader
  from fastNLP.io.data_bundle import DataBundle
  from ..utils import check_loader_paths
  from fastNLP.core.dataset import DataSet, Instance
  from fastNLP.core.log import logger
label_desc: Use image node_id 3 for calling the QuoraLoader obj's underlying member method code with example usage: obj.download() without return types