docstr: shuffle the dataset.
          
docstr_tok: ["shuffle","the","dataset","."]
code: def shuffle(self):
      """shuffle the dataset."""
      cc = list(zip(self.pgl_graph_list, self.graph_label_list))
      random.seed(self.args.seed)
      random.shuffle(cc)
      a, b = zip(*cc)
      self.pgl_graph_list[:], self.graph_label_list[:] = a, b
  
imports: import sys
  import os
  import random
  import pgl
  from pgl.utils.logger import log
  from pgl.graph import Graph, MultiGraph
  import numpy
  import pickle
label_desc: Use image node_id 3 for calling the Dataset obj's underlying member method code with example usage: obj.shuffle() without return types