code: private CachedProviderServiceInstance getCachedServiceInstance(
              String serviceName, String providerAddress) {
          
  		ServiceInstanceId id = new ServiceInstanceId(serviceName, providerAddress);
  		return getCacheServiceInstances().get(id);
         
      }
docs: Get the Cached ProvidedServiceInstance by serviceName and providerAddress.
  
  It is thread safe.
  
  @param serviceName
  the serviceName
  @param providerAddress
  the providerAddress
  @return
  the CachedProviderServiceInstance