class_docstr: Graph Dataloader
      
class_docstr_tok: ["Graph","Dataloader"]
docstr: __len__
docstr_tok: ["__len__"]
code: def __len__(self):
      """__len__"""
      return len(self.dataset)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from __future__ import unicode_literals
  from __future__ import absolute_import
  import os
  import sys
  import time
  import argparse
  import numpy
  import collections
  import paddle
  import paddle.fluid
  import paddle.fluid.layers
  import pgl
  from pgl.utils import mp_reader
  from pgl.utils.logger import log
label_desc: Use image node_id 4 for calling the GraphDataloader obj's underlying member method code with example usage: obj.__len__() and returns: len