@Test
public void doLog_format_argSuppliers_enabled_args_null() throws Exception {

    when(underlyingLogger.isInfoEnabled(testMarker)).thenReturn(true);
    lambdaLogger.doLog(testMarker, Level.INFO, "message format", null, testException);
    verify(underlyingLogger, times(1)).info(eq(testMarker), eq("message format"), eq(testException));
}