The inspect check tested unbound function signatures (3 params unbound vs
2 unbound) but node.manager.create_nio is a bound method — inspect
excludes 'self'. Dynamips bound = 2 (node + nio_settings), standard
bound = 1 (nio_settings). The old '== 3' never matched, so the extra
'node' arg was never passed. Switch to '>= 2' and rewrite the test to
exercise the actual bound-method scenario.