apollo-core/src/main/java/com/ctrip/framework/apollo/core/dto/ApolloConfig.java/ApolloConfig/ApolloConfig
class ApolloConfig:  public ApolloConfig(String appId,
                      String cluster,
                      String namespaceName,
                      String releaseKey) {
    this.appId = appId;
    this.cluster = cluster;
    this.namespaceName = namespaceName;
    this.releaseKey = releaseKey;
  }