code: protected function getMessageFilePath($category, $language)
      {
          $messageFile = Yii::getAlias($this->basePath) . "/$language/";
          if (isset($this->fileMap[$category])) {
              $messageFile .= $this->fileMap[$category];
          } else {
              $messageFile .= str_replace('\\', '/', $category) . '.php';
          }
  
          return $messageFile;
      }
docs: Returns message file path for the specified language and category.
  
  @param string $category the message category
  @param string $language the target language
  @return string path to message file