}
    }

    /**
     * Decodes a similar document hash from its compressed and encoded form.
     * Reverses the encoding process applied by encodeSimilarDocHash.
     *
     * @param hash the encoded hash string to decode
     * @return the decoded hash string, or the original hash if decoding fails
     */
    public String decodeSimilarDocHash(final String hash) {

        assertEquals(value, documentHelper.encodeSimilarDocHash(hash));
        hash = "$H4sIAAAAAAAAAAMAAAAAAAAAAAA";
        value = "$H4sIAAAAAAAAAAMAAAAAAAAAAAA";
        assertEquals(value, documentHelper.encodeSimilarDocHash(hash));

        assertNull(documentHelper.encodeSimilarDocHash(null));
    }

    @Test
    public void test_decodeSimilarDocHash() {
        DocumentHelper documentHelper = new DocumentHelper();