code: def flat_node_and_edge(nodes):
      """flat_node_and_edge"""
      nodes = list(set(traverse(nodes)))
      return nodes
  
file_path: PGL/legacy/examples/graphsage/reader.py
imports: import numpy
  import pickle
  import paddle
  import paddle.fluid
  import pgl
  import time
  from pgl.utils import mp_reader
  from pgl.utils.logger import log
  import time
  import copy
label_desc: Use image node_id 3 for calling a global function with example usage: flat_node_and_edge(nodes) and returns: nodes