code: def test_no_filter(self):
      nf = nx.filters.no_filter
      assert nf()
      assert nf(1)
      assert nf(2, 1)
  
file_path: networkx/networkx/classes/tests/test_filters.py
imports: import pytest
  import networkx
label_desc: Use image node_id 1 for calling the TestFilterFactory obj's underlying member method code with example usage: obj.test_no_filter() without return types