* Convert the value.
     * @param scriptType The script type.
     * @param template The template.
     * @param paramMap The parameters.
     * @return The converted value.
     */
    protected Object convertValue(final String scriptType, final String template, final Map<String, Object> paramMap) {
        if (StringUtil.isEmpty(template)) {
            return StringUtil.EMPTY;
        }

        value = null;
        assertEquals("", dataStore.convertValue(Constants.DEFAULT_SCRIPT, value, paramMap));

        value = "";
        assertEquals("", dataStore.convertValue(Constants.DEFAULT_SCRIPT, value, paramMap));

        value = " ";
        assertNull(dataStore.convertValue(Constants.DEFAULT_SCRIPT, value, paramMap));