class_docstr: Implemetation of graph in order to sample metapath random walk.
      
code: def __init__(self, config):
      self.edge_path = config.edge_path
      self.num_nodes = config.num_nodes
      self.symmetry = config.symmetry
      edge_files = config.edge_files
      node_types_file = config.node_types_file
  
      self.edge_file_list = []
      for pair in edge_files.split(","):
          e_type, filename = pair.split(":")
          filename = os.path.join(self.edge_path, filename)
          self.edge_file_list.append((e_type, filename))
  
      self.node_types_file = os.path.join(
          self.edge_path, node_types_file
      )
  
      self.build_graph()
  
file_path: PGL/legacy/examples/distribute_metapath2vec/graph.py
imports: import argparse
  import sys
  import os
  import numpy
  import pickle
  import tqdm
  import time
  import random
  from pgl.utils.logger import log
  from pgl import heter_graph
label_desc: Use image node_id 1 to create a new m2vGraph object from inherited base classes: object with example: obj = m2vGraph(config)