@Override
        Renderer createComposite(Class<? extends Renderer> rendererClass,
                                         List<Renderer> childRenderers,
                                         Set<Class<? extends Renderer>> excludeRenderers,
                                         Map<String, Param> params, MimeTypes mimeTypes,
                                         ServiceLoader loader)
                throws InvocationTargetException, IllegalAccessException, InstantiationException {
            Renderer renderer = null;
            Constructor<? extends Renderer> c;

            // Try the possible default and composite detector constructors
            if (renderer == null) {
                try {
                    c = rendererClass.getConstructor(ServiceLoader.class, Collection.class);
                    renderer = c.newInstance(loader, excludeRenderers);
                } catch (NoSuchMethodException me) {
                    LOG.debug("couldn't find constructor for service loader + collection for {}",
                            renderer);
                }
            }
            if (renderer == null) {
                try {
                    c = rendererClass.getConstructor(List.class);
                    renderer = c.newInstance(childRenderers);
                } catch (NoSuchMethodException me) {
                    LOG.debug("couldn't find constructor for Renderer(List) for {}",
                            rendererClass);
                }
            }
            return renderer;
        }
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