code: def setup_class(cls):
      global np
      np = pytest.importorskip("numpy")
      pytest.importorskip("scipy")
      super().setup_class()
  
imports: import math
  import pytest
  import networkx
label_desc: Use image node_id 1 for calling the TestKatzCentralityDirectedNumpy obj's underlying member method code with example usage: obj.setup_class(cls) without return types