PackageDefinition packageDefinition = new PackageDefinition(packageName);
packageDefinition.setContainedScope(packageScope);
fileScope.addDefinition(packageDefinition);
Multiname mname = Multiname.crackDottedQName(getProject(), qname);
INamespaceDefinition packageNS = Iterables.getOnlyElement(mname.getNamespaceSet());
ClassDefinition classDefinition = new ClassDefinition(mname.getBaseName(), (INamespaceReference)packageNS);
IReference baseClass = ReferenceFactory.packageQualifiedReference(getProject().getWorkspace(), fxgBaseClassName);
classDefinition.setBaseClassReference(baseClass);
TypeScope classScope = new TypeScope(packageScope, classDefinition);
classScope.setContainingDefinition(classDefinition);