// also has the correct package, namely "__AS3__.vec".
INamespaceDefinition vectorImplPackage = ((CompilerProject)project).getWorkspace().getPackageNamespaceDefinitionCache().get(IASLanguageConstants.Vector_impl_package, true);
IResolvedQualifiersReference vectorReference = ReferenceFactory.resolvedQualifierQualifiedReference(project.getWorkspace(), vectorImplPackage, baseName);
IDefinition vectorIDefinition = vectorReference.resolve(project);
assert vectorIDefinition instanceof IClassDefinition :
"Unable to find: " + vectorReference.getDisplayString();
return (IClassDefinition) vectorIDefinition;
}