@Test
public void copyStreamZipped() throws IOException {

    File tempFile = folder.newFile();
    Map<String, File> files = new HashMap<String, File>();
    files.put("newName", tempFile);
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    OutputWriterHelper.copyToStreamZipped(files, out);
    assertFalse("temporary file not deleted", tempFile.exists());
    assertTrue(out.size() > 0);
}