assertEquals(hash, documentHelper.decodeSimilarDocHash(value));
        hash = "";
        value = "";
        assertEquals(hash, documentHelper.decodeSimilarDocHash(value));

        assertNull(documentHelper.decodeSimilarDocHash(null));
    }

    public void test_appendLineNumber() {
        DocumentHelper documentHelper = new DocumentHelper();

            }
            return null;
        } catch (final Exception e) {
            throw new CrawlingAccessException("Failed to parse " + url, e);
        }
    }

    public String decodeSimilarDocHash(final String hash) {
        if (hash != null && hash.startsWith(SIMILAR_DOC_HASH_PREFIX) && hash.length() > SIMILAR_DOC_HASH_PREFIX.length()) {