Bug 286678 UI model and propagation of context values: containers with variables
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/workbench/ui/internal/Workbench.java
IConfigurationElement[] factories = registry
				.getConfigurationElementsFor("org.eclipse.e4.workbench.partfactory"); 
		
		
		int offset = 0;
		for (int i = 0; i < factories.length; i++) {
			String clsSpec = factories[i].getAttribute("class"); 
			if (clsSpec.indexOf("Legacy") >= 0 
					|| clsSpec.indexOf("PartSash") >= 0) { 
				IConfigurationElement tmp = factories[offset];
				factories[offset++] = factories[i];
				factories[i] = tmp;
			}
		}
		for (int i = 0; i < factories.length; i++) {
			AbstractPartRenderer factory = null;
			try {
				factory = (AbstractPartRenderer) factories[i].createExecutableExtension("class"); 
			} catch (CoreException e) {
				e.printStackTrace();
			}
			if (factory != null) {
				factory.init(r, context, f);
				ContextInjectionFactory.inject(factory, context);
				r.addPartFactory(factory);
			}
		}
		
		context.set(PartRenderingEngine.SERVICE_NAME, r);
	}