apollo-client/src/main/java/com/ctrip/framework/apollo/spi/DefaultConfigRegistry.java/DefaultConfigRegistry/register
class DefaultConfigRegistry:  @Override
  public void register(String namespace, ConfigFactory factory) {
    if (m_instances.containsKey(namespace)) {
      s_logger.warn("ConfigFactory({}) is overridden by {}!", namespace, factory.getClass());
    }

    m_instances.put(namespace, factory);
  }