branch : master , version : 2.7.0-SNAPSHOT
ServiceConfig#doExportUrlsFor1Protocol , line 482

<img width="890" alt="image" src="https://user-images.githubusercontent.com/6971152/41273922-035827c2-6e4e-11e8-8a72-71562d138cf9.png">

The type of Constant.SCOPE_Xxx is String already , no need to call toString() again
port = intPort;
            } catch (Exception e) {
                throw new IllegalArgumentException("Specified invalid port from env value:" + configPort);
            }
        }
        return port;
    }
    private String getValueFromConfig(ProtocolConfig protocolConfig, String key) {
        String protocolPrefix = protocolConfig.getName().toUpperCase() + "_";
        String port = ConfigUtils.getSystemProperty(protocolPrefix + key);
        if (port == null || port.length() == 0) {
            port = ConfigUtils.getSystemProperty(key);
        }
        return port;
    }
    private void checkDefault() {
        if (provider == null) {
            provider = new ProviderConfig();
        }
        appendProperties(provider);
    }
    private void checkProtocol() {
        if ((protocols == null || protocols.isEmpty())
                && provider != null) {
            setProtocols(provider.getProtocols());
        }
        
        if (protocols == null || protocols.isEmpty()) {
            setProtocol(new ProtocolConfig());
        }