Bug 314847 Command parameters are never cleared
tests/org.eclipse.e4.core.commands.tests/src/org/eclipse/e4/core/commands/tests/HandlerTest.java
workbenchContext.remove(Info.class.getName());
		assertNull(wHS.executeHandler(cmd));
		
		workbenchContext.set(ACTIVE_INFO_ID, helloInfo);
		assertEquals(helloInfo, wHS.executeHandler(cmd));
		
		workbenchContext.remove(ACTIVE_INFO_ID);
		assertNull(wHS.executeHandler(cmd));
	}
	private IEclipseContext workbenchContext;
	@Override
	protected void setUp() throws Exception {
		IEclipseContext globalContext = TestActivator.getDefault().getGlobalContext();
		workbenchContext = globalContext.createChild("workbenchContext");
		defineCommands(workbenchContext);
	}
	@Override
	protected void tearDown() throws Exception {
		workbenchContext.dispose();
	}
	private void defineCommands(IEclipseContext context) {
		ECommandService cs = (ECommandService) workbenchContext
				.get(ECommandService.class.getName());
		Category category = cs.defineCategory(TEST_CAT1, "CAT1", null);
		cs.defineCommand(TEST_ID1, "ID1", null, category, null);
		cs.defineCommand(TEST_ID2, "ID2", null, category, null);
	}
}