@Override
        ConfigurableThreadPoolExecutor createComposite(
                Class<? extends ConfigurableThreadPoolExecutor> compositeClass,
                List<ConfigurableThreadPoolExecutor> children,
                Set<Class<? extends ConfigurableThreadPoolExecutor>> excludeChildren,
                Map<String, Param> params, MimeTypes mimeTypes, ServiceLoader loader)
                throws InstantiationException {
            throw new InstantiationException("Only one executor service supported");
        }
Gets parameters from a given

@param el xml node which has {@link #PARAMS_TAG_NAME} child
@return Map of key values read from xml
tika-core/src/main/java/org/apache/tika/config/TikaConfig.java