code: @Override
      public Map<String, String> getProperties() {
  
          Map<String, String> props = new HashMap<>();
          Map<String, String> serverXMLVariables = getServerXMLVariables();
          if (serverXMLVariables != null) {
              props.putAll(serverXMLVariables);
          }
  
          return props;
      }
docs: {@inheritDoc}