// Happy path: ensureConnected returns true/false
    @ParameterizedTest
    @DisplayName("ensureConnected indicates if it connected during call")
    @ValueSource(booleans = { true, false })
    void ensureConnected_returns(boolean connectedDuringCall) throws Exception {
        when(transport.ensureConnected()).thenReturn(connectedDuringCall);
        assertEquals(connectedDuringCall, transport.ensureConnected());