code: public boolean isValid() {
          if (PluggableTaskConfigStore.store().preferenceFor(pluginConfiguration.getId()) == null) {
              addError(TYPE, String.format("Could not find plugin for given pluggable id:[%s].", pluginConfiguration.getId()));
          }
  
          configuration.validateTree();
  
          return (errors.isEmpty() && !configuration.hasErrors());
      }
docs: This method is called from PluggableTaskService to validate Tasks.