@Test
public void testLog_timeAndFields_eventProvided() {

    Map<String, String> fields = new HashMap<>();
    fields.put(LOG_KEY_EVENT, "my-key-event");
    fields.put("foo", "bar");
    Span result = undertest.log(100L, fields);
    assertSame(result, undertest);
    assertEquals(1, grpcSpan.getLogsCount());
    Log logRecord = grpcSpan.getLogs(0);
    Map<String, String> fieldMap = getLogFieldMap(logRecord);
    assertEquals("my-key-event", fieldMap.get(LOG_KEY_EVENT));
    assertEquals("bar", fieldMap.get("foo"));
    assertEquals(100L, Util.protoTimeToEpochMicros(logRecord.getTimestamp()));
}