Oop error

saya mengikuti tutorial oop login dan register sudah saya ikut sama persis masih ada error, dimana kesalahan saya

<?php

class Validation{

  private $_passed = false;
          $_errors = array();

 public function check( $items = array() ){
    foreach ($items as $item => $rules) {
      foreach ($rules as $rule => $rule_value) {

        switch ($rule) {
          case 'required':
          if( trim(Input::get($item)) == false && $rule_value == true){
            $this->addError(" $item wajib diisi ");
          }
            break;
            case 'min':
            if( strlen(Input::get($item)) < $rule_value ){
              $this->addError(" $item minimal $rule_value karakter ");
            }
              break;
                case 'max':
                if( strlen(Input::get($item)) > $rule_value ){
                  $this->addError(" $item maksimal $rule_value karakter ");
                }
                  break;

          default:
            break;
        }
      } //end first foreach
    }

    if(empty($this->_errors)){
      $this->_passed = true;
    }

    return $this;
  }

  private function addError($error){
    $this->_errors[] = $error;
  }

  public function errors(){
    return $this->_errors;
  }

  public function passed(){
    return $this->_passed;
  }

}

?>