protected void addAlive(ProviderInfo providerInfo, ClientTransport transport) {
        if (checkState(providerInfo, transport)) {
            aliveConnections.put(providerInfo, transport);
        }
    }
Add alive.

@param providerInfo the provider
@param transport    the transport
core-impl/client/src/main/java/com/alipay/sofa/rpc/client/AllConnectConnectionHolder.java