@Test
public void testStart_noStartTimeProvided() {

    // start the span
    io.opentracing.Span otSpan = undertest.start();
    assertNotNull(otSpan);
    assertTrue(otSpan instanceof Span);
    Span lsSpan = (Span) otSpan;
    assertTrue(lsSpan.getStartTimestampRelativeNanos() + " was not greater than zero",
            lsSpan.getStartTimestampRelativeNanos() > 0);
    assertTrue(lsSpan.getGrpcSpan().getStartTimestamp() + " was not greater than zero",
            Util.protoTimeToEpochMicros(lsSpan.getGrpcSpan().getStartTimestamp()) > 0);
    verifyResultingSpan(lsSpan);
}