Bug 280846 [UI][CSS] Null styling engine required in main context for tests to run
bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/workbench/swt/internal/WorkbenchApplication.java
if (cssURI != null) {
						WorkbenchStylingSupport.initializeStyling(display,
								cssURI, cssResourcesURI, appContext);
					} else {
						WorkbenchStylingSupport
								.initializeNullStyling(appContext);
					}
					Workbench wb = new Workbench(Activator.getDefault()
							.getInstanceLocation(), RegistryFactory
							.getRegistry(), Activator.getDefault()
							.getBundleAdmin(), appContext,
							new WorkbenchWindowHandler());
					wb.setWorkbenchModelURI(initialWorkbenchDefinitionInstance);
					wb.createUIFromModel();
					wb.run();
				} catch (ThreadDeath th) {
					throw th;
				} catch (Exception ex) {
					ex.printStackTrace();
				} catch (Error err) {
					err.printStackTrace();
				}
			}
		});
		return IApplication.EXIT_OK;
	}
	public void stop() {
	}
}