apollo-client/src/main/java/com/ctrip/framework/apollo/internals/PlainTextConfigFile.java/PlainTextConfigFile/hasContent
class PlainTextConfigFile:  @Override
  public boolean hasContent() {
    if (m_configProperties.get() == null) {
      return false;
    }
    return m_configProperties.get().containsKey(ConfigConsts.CONFIG_FILE_CONTENT_KEY);
  }