private void assertDebugLogIs(String message) {
    assertThat(getLoggingEvents())
      .hasSize(1)
      .filteredOn(event -> event.getLevel().equals(Level.DEBUG))
      .extracting(event -> unprefixIdString(event.getMessage()))
      .containsOnly(message);
  }
Tags in zipkin v2 model are stringly typed.
zipkin-collector/core/src/test/java/zipkin2/collector/CollectorTest.java