protected function _getRule($rule)
    {
        if ($rule instanceof FilterInterface) {
            return $rule;
        }

        $rule = (string) $rule;
        return $this->getPluginManager()->get($rule);
    }
protected function _getRule($rule)
    {
        if ($rule instanceof FilterInterface) {
            return $rule;
        }

        $rule = (string) $rule;
        return $this->getPluginManager()->get($rule);
    }
protected function _getRule ( $ rule ) { if ( $ rule instanceof FilterInterface ) { return $ rule ; } $ rule = ( string ) $ rule ; return $ this -> getPluginManager ( ) -> get ( $ rule ) ; }
Resolve named filters and convert them to filter objects.

@param  string $rule
@return FilterInterface
Resolve named filters and convert them to filter objects .