private ProviderInfo selectForKey(long hash) {
            Map.Entry<Long, ProviderInfo> entry = virtualNodes.ceilingEntry(hash);
            if (entry == null) {
                entry = virtualNodes.firstEntry();
            }
            return entry.getValue();
        }
Select for key.

@param hash the hash
@return the provider
core-impl/client/src/main/java/com/alipay/sofa/rpc/client/lb/ConsistentHashLoadBalancer.java