** Implement to define a renderer for form errors.
**
** To use your skin, define it as a service of type 'ErrorSkin':
**
** syntax: fantom
**
** static Void defineServices(ServiceDefinitions defs) {
** defs.add(ErrorSkin#, MyErrorSkin#)
** }
**
** The default error skin renders the following HTML:
**
** syntax: html
**
** <div class='formBean-errors'>
** <div class='formBean-banner'>#BANNER</div>
** <ul>
** <li> Error 1 </li>
** <li> Error 2 </li>
** </ul>
** </div>
**
** To change the banner message, set a message with the key 'errors.<beanType.name>.banner' or 'errors.banner'.
**
** 'ErrorSkins' should *usually* be 'const' classes.
mixin ErrorSkin {
** Renders form bean errors to HTML.
abstract Str render(FormBean formBean)
}