jetbrick-ioc/src/main/java/jetbrick/ioc/MutableIoc.java
@Override
    public Object getBean(String name) {
        IocObject iocObject = pool.get(name);
        if (iocObject == null) {
            return null;
        }
        return iocObject.getObject();
    }
@Override
    public Object getBean(String name) {
        IocObject iocObject = pool.get(name);
        if (iocObject == null) {
            return null;
        }
        return iocObject.getObject();
    }
获取一个 Bean