/**
  * Apply multiple functions to variable.
  * @param  mixed  $var
  * @param  string $functions
  * @return mixed
  */
 protected function batch($var, $functions)
 {
     foreach (explode('|', $functions) as $function) {
         if ($this->engine->doesFunctionExist($function)) {
             $var = call_user_func(array($this, $function), $var);
         } elseif (is_callable($function)) {
             $var = call_user_func($function, $var);
         } else {
             throw new LogicException('The batch function could not find the "' . $function . '" function.');
         }
     }
     return $var;
 }