Bug 314847 Command parameters are never cleared
tests/org.eclipse.e4.core.commands.tests/src/org/eclipse/e4/core/commands/tests/HandlerTest.java
private static final String ACTIVE_INFO_ID = "activeInfo";
	private static final String TEST_ID2 = "test.id2";
	private static final String TEST_ID1 = "test.id1";
	private static final String TEST_CAT1 = "test.cat1";
	static class CallHandler {
		public boolean q1;
		public boolean q2;
		@CanExecute
		public boolean canExecute() {
			q1 = true;
			return true;
		}
		@Execute
		public Object execute() {
			q2 = true;
			if (q1) {
				return Boolean.TRUE;
			}
			return Boolean.FALSE;
		}
	}
	public void testCallHandler() throws Exception {
		EHandlerService hs = (EHandlerService) workbenchContext
				.get(EHandlerService.class.getName());
		CallHandler handler = new CallHandler();
		hs.activateHandler(TEST_ID1, handler);