// Test default constructor
        ExtractData data = new ExtractData();
        assertNotNull(data);
        assertNull(data.getContent());
        assertNotNull(data.getKeySet());
        assertTrue(data.getKeySet().isEmpty());
    }

    public void test_constructorWithContent() {
        // Test constructor with content
        String content = "Test content";

        return metadata.get(key);
    }

    /**
     * Gets the set of all metadata keys.
     *
     * @return the set of metadata keys
     */
    public Set<String> getKeySet() {
        return metadata.keySet();
    }

    /**
     * Gets the extracted content.
     *
     * @return the extracted content
     */
    public String getContent() {

            }
            if (getLogger().isDebugEnabled()) {
                getLogger().debug("ExtractData: {}", extractData);
            }
            // meta
            extractData.getKeySet().stream().filter(k -> extractData.getValues(k) != null).forEach(key -> {
                final String[] values = extractData.getValues(key);
                metaDataMap.put(key, values);

                // meta -> content