class_docstr: Implementation of Dataset class
  
  This is a simple implementation of loading and processing dataset for metapath2vec model.
  
  Args:
      config: dict, some configure parameters.
class_docstr_tok: ["Implementation","of","Dataset","class","This","is","a","simple","implementation","of","loading","and","processing","dataset","for","metapath2vec","model",".","Args",":","config",":","dict",",","some","configure","parameters","."]
docstr: Generate train pairs(src, pos, negs) for training model.
          
docstr_tok: ["Generate","train","pairs","(","src",",","pos",",","negs",")","for","training","model","."]
code: def pairs_generator(self, walkpath_files):
      """Generate train pairs(src, pos, negs) for training model."""
  
      def wrapper():
          """wrapper for multiprocess calling."""
          for walks in self.walk_from_files(walkpath_files):
              res = self.gen_pairs(walks)
              yield res
  
      return wrapper
  
file_path: PGL/legacy/examples/metapath2vec/Dataset.py
imports: import sys
  import os
  import glob
  import numpy
  import tqdm
  import time
  import logging
  import random
  from pgl import heter_graph
  import pickle
label_desc: Use image node_id 7 for calling the Dataset obj's underlying member method code with example usage: obj.pairs_generator(walkpath_files) and returns: wrapper