public abstract byte[] encode(MutableSpan input);
@Test void rootServerSpan_JSON_V2_shared() {
    rootServerSpan.setShared();

    assertThat(new String(encoder.encode(rootServerSpan), UTF_8))
        .isEqualTo(
            "{\"traceId\":\"dc955a1d4768875d\",\"id\":\"dc955a1d4768875d\",\"kind\":\"SERVER\",\"name\":\"get\",\"timestamp\":1510256710021866,\"duration\":1117,\"localEndpoint\":{\"serviceName\":\"isao01\",\"ipv4\":\"10.23.14.72\"},\"tags\":{\"http.path\":\"/rs/A\",\"location\":\"T67792\",\"other\":\"A\"},\"shared\":true}");
  }