apollo-client/src/main/java/com/ctrip/framework/apollo/spring/property/SpringValueRegistry.java/SpringValueRegistry/get
class SpringValueRegistry:  public Collection<SpringValue> get(BeanFactory beanFactory, String key) {
    Multimap<String, SpringValue> beanFactorySpringValues = registry.get(beanFactory);
    if (beanFactorySpringValues == null) {
      return null;
    }
    return beanFactorySpringValues.get(key);
  }