@Test
public void shouldReturnZippedInputStream() throws IOException {

    // given
    final ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
    try (GZIPOutputStream sampleContent = new GZIPOutputStream(outputStream)) {
        sampleContent.write('a');
    }
    when(delegate.get(any())).thenReturn(new ByteArrayInputStream(outputStream.toByteArray()));
    ContentCache contentCache = new ZippedContentCache(delegate);
    // when
    final InputStream stream = contentCache.get(() -> StringUtils.EMPTY);
    // then
    verify(delegate, times(1)).get(any());
    assertEquals(GZIPInputStream.class, stream.getClass());
}