code: def test_preflow_push_global_relabel(self):
      G = read_graph("gw1")
      R = preflow_push(G, 1, len(G), global_relabel_freq=50)
      assert R.graph["flow_value"] == 1202018
  
file_path: networkx/networkx/algorithms/flow/tests/test_maxflow_large_graph.py
imports: import bz2
  import importlib.resources
  import os
  import pickle
  import pytest
  import networkx
  from networkx.algorithms.flow import boykov_kolmogorov, build_flow_dict, build_residual_network, dinitz, edmonds_karp, preflow_push, shortest_augmenting_path
label_desc: Use image node_id 6 for calling the TestMaxflowLargeGraph obj's underlying member method code with example usage: obj.test_preflow_push_global_relabel() without return types