code: public static void loadDnsCacheConfig() {
          final String DCM_CONFIG_FILE_NAME_KEY = "dcm.config.filename";
          final String dcmConfigFileName = System.getProperty(DCM_CONFIG_FILE_NAME_KEY, "dns-cache.properties");
          loadDnsCacheConfig(dcmConfigFileName);
      }
docs: Load dns config from properties file {@code dns-cache.properties} on classpath, then set to dns cache.
  <p>
  {@code dns-cache.properties} can be reset/customized by {@code JVM -D option} {@code dcm.config.filename}
  
  @throws DnsCacheManipulatorException Operation fail
  @see DnsCacheManipulator#setDnsCache(java.util.Properties)
  @see DnsCacheManipulator#loadDnsCacheConfig(java.lang.String)