apollo-client-config-data/src/main/java/com/ctrip/framework/apollo/config/data/importer/ApolloConfigDataResource.java/ApolloConfigDataResource/toString
class ApolloConfigDataResource:  @Override
  public String toString() {
    return "ApolloConfigDataResource{" +
        "namespace='" + namespace + '\'' +
        '}';
  }