public function isRequired($flag)
    {
        $rule = $this->getRule($flag);
        return $rule && $rule['required'] === self::PARAM_REQUIRED;
    }
public function isRequired($flag)
    {
        $rule = $this->getRule($flag);
        return $rule && $rule['required'] === self::PARAM_REQUIRED;
    }
public function isRequired ( $ flag ) { $ rule = $ this -> getRule ( $ flag ) ; return $ rule && $ rule [ 'required' ] === self :: PARAM_REQUIRED ; }
Returns true if the given flag is required.

@return  bool
Returns true if the given flag is required .