Description:
------------
Derived classes of the same base class can access each other's protected method and protected property.

Test script:
---------------
class Base {
protected function foo() {
   echo 'foo';
}
}

class A extends Base {

}

class B extends Base {

public function bar() {
  $a = new A();
  // in fact, it is ok, and will echo foo.
  // but I think it should not access
  $a->foo();
}

}

(new B())->bar();