* @param filterClass Filter the returned plugins after calling the plugin manager.
*/
public PatternParser(final Configuration config, final String converterKey, final Class<?> expectedClass,
final Class<?> filterClass) {
this.config = config;
final PluginManager manager = new PluginManager(converterKey, expectedClass);
manager.collectPlugins();
final Map<String, PluginType> plugins = manager.getPlugins();
final Map<String, Class<PatternConverter>> converters = new HashMap<String, Class<PatternConverter>>();
for (final PluginType type : plugins.values()) {
try {
final Class<PatternConverter> clazz = type.getPluginClass();