code: private Dictionary<String,String> getConfiguration() {
          Dictionary<String,String> config = new Hashtable<String,String>();
          for (ConfigKey key : ConfigKey.values()) {
              String value = getConfiguration(key);
              if (value != null) {
                  config.put(key.getKeyValue(),value);
              }
          }
          String jolokiaId = NetworkUtil.replaceExpression(config.get(ConfigKey.AGENT_ID.getKeyValue()));
          if (jolokiaId == null) {
              config.put(ConfigKey.AGENT_ID.getKeyValue(),
                         NetworkUtil.getAgentId(hashCode(),"osgi"));
          }
          config.put(ConfigKey.AGENT_TYPE.getKeyValue(),"osgi");
          return config;
      }
docs: Customizer for registering servlet at a HttpService