public List<ValidationProvider<?>> getValidationProviders() {
	ClassLoader classloader = GetClassLoader.fromContext();
	if ( classloader == null ) {
		classloader = GetClassLoader.fromClass( DefaultValidationProviderResolver.class );
	}

	List<ValidationProvider<?>> providers;
	synchronized ( providersPerClassloader ) {
		providers = providersPerClassloader.get( classloader );
	}

	if ( providers == null ) {
		providers = new ArrayList<ValidationProvider<?>>();
		String name = null;
		try {
			Enumeration<URL> providerDefinitions = classloader.getResources( SERVICES_FILE );
			while ( providerDefinitions.hasMoreElements() ) {
                          ...
			}
		}
		 
                ...
			
		synchronized ( providersPerClassloader ) {
			providersPerClassloader.put( classloader, providers );
		}
	}

	return providers;
}