@Test
public void testIsServer() throws Exception {

    SofaTracerSpan clientSpan = (SofaTracerSpan) this.sofaTracer.buildSpan("testIsClient")
        .withStartTimestamp(111).start();
    clientSpan.setTag(Tags.SPAN_KIND.getKey(), Tags.SPAN_KIND_CLIENT);
    //
    SofaTracerSpan serverSpan = (SofaTracerSpan) this.sofaTracer.buildSpan("testIsServer")
        .withStartTimestamp(111).start();
    serverSpan.setTag(Tags.SPAN_KIND.getKey(), Tags.SPAN_KIND_SERVER);
    //
    assertTrue(clientSpan.isClient());
    assertTrue(serverSpan.isServer());
}