def METHOD_NAME(self):
    propagator = CompositePropagator([self.mock_propagator_0])
    new_carrier = {}
    propagator.inject(new_carrier)
    self.assertEqual(new_carrier, {"mock-0": "data"})
    context = propagator.extract(
        carrier=new_carrier, context={}, getter=get_as_list
    )
    self.assertEqual(context, {"mock-0": "context"})