Bug 318930 Be lazy: Convert HandlerActivation from RunAndTrack to ContextFunction (pull instead of push)
bundles/org.eclipse.e4.core.commands/src/org/eclipse/e4/core/commands/internal/HandlerServiceImpl.java
paramsContext, Boolean.TRUE));
			return result.booleanValue();
		} finally {
			paramsContext.dispose();
		}
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.e4.core.commands.EHandlerService#deactivateHandler(java.lang.String,
	 * java.lang.Object)
	 */
	public void deactivateHandler(String commandId, Object handler) {
		context.remove(H_ID + commandId);
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @seeorg.eclipse.e4.core.commands.EHandlerService#executeHandler(org.eclipse.core.commands.
	 * ParameterizedCommand)
	 */
	public Object executeHandler(ParameterizedCommand command) {
		String commandId = command.getId();
		Object handler = lookUpHandler(context, commandId);
		if (handler == null) {
			return null;
		}
		IEclipseContext paramsContext = createParamsContext(command);
		try {
			Object rc = ContextInjectionFactory.invoke(handler, CanExecute.class, paramsContext,