code: def test_is_tripwire():
      assert not is_tripwire(object())
      assert is_tripwire(TripWire("some message"))
  
imports: import pytest
  from ..tripwire import TripWire, TripWireError, is_tripwire
label_desc: Use image node_id 1 for calling a global function with example usage: test_is_tripwire() without return types