def METHOD_NAME(self):
    # ensure distributed tracing can be disabled manually
    cfg = config.get_from(self.session)
    cfg["distributed_tracing"] = False
    adapter = Adapter()
    self.session.mount("mock", adapter)
    with self.tracer.trace("root"):
        def matcher(request):
            return self.headers_not_here(self.tracer, request)
        adapter.register_uri("GET", "mock://datadog/foo", additional_matcher=matcher, text="bar")
        resp = self.session.get("mock://datadog/foo")
        assert 200 == resp.status_code
        assert "bar" == resp.text