@Test
public void doesNotChangeTheSource() {

    // given
    CompositeByteBuf expectedSource = createDefaultTestByteBuf();
    ItemSource itemSource = new ByteBufItemSource(expectedSource, mock(ReleaseCallback.class));
    // when
    Object actualSource = itemSource.getSource();
    // then
    assertEquals(expectedSource, actualSource);
    assertTrue(expectedSource == actualSource);
}