code: protected function isFileLoaded($locale, $file)
  	{
  		if (array_key_exists($locale, $this->translations) === false)
  		{
  			return false;
  		}
  
  		if (array_key_exists($file, $this->translations[$locale]) === false)
  		{
  			return false;
  		}
  
  		return true;
  	}
docs: checks if a file for a given locale loaded
  
  @param string $locale
  @param string $file
  @return boolean