class_docstr: Unit tests for the local_bridge function.
code: def setup_class(cls):
      cls.BB = nx.barbell_graph(4, 0)
      cls.square = nx.cycle_graph(4)
      cls.tri = nx.cycle_graph(3)
  
file_path: networkx/networkx/algorithms/tests/test_bridges.py
imports: import pytest
  import networkx
label_desc: Use image node_id 1 for calling the TestLocalBridges obj's underlying member method code with example usage: obj.setup_class(cls) without return types