@Test
public void testStartNestedSpanWhenSpanNotNull() {

    // Setup
    final String name = "name";
    final String event = "event";
    final Span span = mock(Span.class);
    final Span nestedSpan = mock(Span.class);
    when(mockTracer.createSpan(anyString(), any(Span.class))).thenReturn(nestedSpan);
    // Run the test
    final Span result = kermossTracerUnderTest.startNestedSpan(name, event, span);
    // Verify the results
    verify(nestedSpan).logEvent(same(event));
    assertEquals(result, nestedSpan);
}