code: def test_verify_parameter_none_required_false_passes(verify_func):
      assert verify_func(None, required=False) is None
  
imports: import pytest
  import graphviz
  from graphviz import parameters
label_desc: Use image node_id 3 for calling a global function with example usage: test_verify_parameter_none_required_false_passes(verify_func) without return types