in src/main/java/com/alibaba/csp/sentinel/adapter/dubbo/fallback/DubboFallbackRegistry.java [48:51]
public static void setProviderFallback(DubboFallback providerFallback) {
AssertUtil.notNull(providerFallback, "providerFallback cannot be null");
DubboFallbackRegistry.providerFallback = providerFallback;
}