throw new CrawlerSystemException("key or value is null.");
        }

        featureMap.put(key, value);
    }

    /**
     * Adds a parser property configuration.
     *
     * @param key the property key
     * @param value the property value
     * @throws CrawlerSystemException if key or value is null
     */
    public void addProperty(final String key, final String value) {

    /** The property name for access timeout. */
    public static final String ACCESS_TIMEOUT_PROPERTY = "accessTimeout";

    /** The property name for maximum content length. */
    public static final String MAX_CONTENT_LENGTH = "maxContentLength";

    /** The property name for maximum cached content size. */

        }

        featureMap.put(key, value);
    }

    /**
     * Adds a property to the extractor.
     *
     * @param key   the key of the property
     * @param value the value of the property
     */
    public void addProperty(final String key, final String value) {
        if (StringUtil.isBlank(key) || StringUtil.isBlank(value)) {

    }

    /** An empty string constant. */
    public static final String EMPTY_STRING = "";

    /** The system property name for user dictionary encoding. */
    public static final String USER_DICT_ENCODING = "fess.user.dict.encoding";

    /** The system property name for user dictionary path. */
    public static final String USER_DICT_PATH = "fess.user.dict.path";

    /** The text separator. */

    /** Property name for proxy port setting */
    public static final String PROXY_PORT_PROPERTY = "proxyPort";

    /** Property name for proxy authentication scheme setting */
    public static final String PROXY_AUTH_SCHEME_PROPERTY = "proxyAuthScheme";

    /** Property name for proxy credentials setting */
    public static final String PROXY_CREDENTIALS_PROPERTY = "proxyCredentials";

    /** Property key for SMB authentications configuration. */
    public static final String SMB_AUTHENTICATIONS_PROPERTY = "smbAuthentications";

    /** Property key for SMB allowed SID entries. */
    public static final String SMB_ALLOWED_SID_ENTRIES = "smbAllowedSidEntries";

    /** Property key for SMB denied SID entries. */

    /** Property key for SMB1 authentications configuration. */
    public static final String SMB_AUTHENTICATIONS_PROPERTY = "smb1Authentications";

    /** Property key for SMB1 access control entries. */
    public static final String SMB_ACCESS_CONTROL_ENTRIES = "smb1AccessControlEntries";

    /** Property key for SMB1 allowed SID entries. */

    }

    /**
     * Gets the map of parser properties.
     *
     * @return the property map
     */
    public Map<String, String> getPropertyMap() {
        return propertyMap;
    }

    /**
     * Sets the map of parser properties.
     *
     * @param propertyMap the property map to set
     */
    public void setPropertyMap(final Map<String, String> propertyMap) {

            fail("Should throw exception with null container");
        } catch (NullPointerException e) {
            // Expected
        }
    }

    /**
     * Test concurrent property access
     */
    public void test_concurrentPropertyAccess() throws Exception {
        final int threadCount = 10;
        final int iterationsPerThread = 100;

                parser.setProperty(XMLConstants.ACCESS_EXTERNAL_SCHEMA, StringUtil.EMPTY);
            } catch (final Exception e) {
                if (logger.isDebugEnabled()) {
                    logger.debug("Failed to set a property.", e);
                }
            }
            // parse a content
            parser.parse(is, handler);

            return handler.getDataMap();
        } catch (final Exception e) {