code: public ProcessingParameters mergedParams(Map<String, String> pConfig) {
          if (pConfig == null) {
              return this;
          } else {
              Map<ConfigKey,String> newParams = new HashMap<ConfigKey, String>();
              newParams.putAll(params);
              newParams.putAll(convertToConfigMap(pConfig));
              return new ProcessingParameters(newParams, pathInfo);
          }
      }
docs: Merge in a configuration and return a ProcessingParameters object representing
  the merged values
  
  @param pConfig config to merge in
  @return a new ProcessingParameters instance if the given config is not null. Otherwise this object
  is returned.