CompilerContext cc = (CompilerContext)
ContextService.getContext(CompilerContext.CONTEXT_ID);
ClassFactory classFactory = cc.getClassFactory();
TypeCompilerFactory tcf = cc.getTypeCompilerFactory();
Class<?> derbyAggregatorInterface = classFactory.loadApplicationClass( "org.apache.derby.agg.Aggregator" );
Class<?> userAggregatorClass = classFactory.loadApplicationClass( _alias.getJavaClassName() );
Class[][] typeBounds = classFactory.getClassInspector().getTypeBounds
( derbyAggregatorInterface, userAggregatorClass );