@Test
public void testDownloadFilesWhenThereIsSearchingResult() throws ServletException, IOException {

    //GIVEN
    List<String> pair = new ArrayList<String>();
    pair.add("first");
    pair.add("test");
    List<List<String>> list = new ArrayList<>();
    list.add(pair);
    given(session.getAttribute(SEARCH_RESULT_KEY)).willReturn(list);
    given(response.getOutputStream()).willReturn(outputStream);
    //WHEN
    underTest.downloadFiles(session, response);
    //THEN
    verify(fileZipper).createZipWithFiles(list, outputStream);
    verify(session).removeAttribute(SEARCH_RESULT_KEY);
}