private void initializeFunctions( UrlRewriteRulesDescriptor rules ) {
for( String name : UrlRewriteFunctionDescriptorFactory.getNames() ) {
try {
UrlRewriteFunctionDescriptor descriptor = rules.getFunction( name );
UrlRewriteFunctionProcessor processor = UrlRewriteFunctionProcessorFactory.create( name, descriptor );
processor.initialize( environment, descriptor );
functions.put( name, processor );
} catch( Exception e ) {
// Ignore it and it won't be available as a function.
LOG.failedToInitializeRewriteFunctions( e );
}