code: protected boolean addCustomDissector(Token token, String fieldType, String fieldName) {
          if (customDissector == null) {
              return true;
          }
          try {
              Dissector dissector = customDissector.getNewInstance();
              dissector.setInputType(fieldType);
              if (!dissector.initializeFromSettingsParameter(fieldName)) {
                  LOG.error("Unable to INITIALIZE custom dissector for {}:{}", fieldType, fieldName);
                  return false;
              }
              token.setCustomDissector(dissector);
          } catch (Exception e) {
              LOG.error("Unable to add custom dissector for {}:{} because of : {}", fieldType, fieldName, e.getMessage());
              return false;
          }
          return true;
      }
docs: --------------------------------------------