title: Method/function overrides in Codeigniter
body: <p>I want to override the validation_errors() method of the form helper in CodeIgniter for one controller only, so that it will display a single error message (as a sentence in plain english) instead of the detailed line item summary. I've tried defining a validation_errors() function in my controller, which is what I usually do with Silverstripe's Sapphire framework, but this won't with CI.</p>
  
  <p>What's the best way to override methods for a case by case basis?</p>