How do I mock a protected property of a an object.

Given
```
Class A {
protected $x = false;

public function methodA()
{
if($x){ return 'FOO'; }
return 'BAR';
}
}
```

My test is -
```
$a = new A();

\Aspectmock\Test::double($a,['x' => true]);

$this->assertEquals('BAR', $a->methodA() );
```

I get `null`.

How do I solve this?

Reproduce the example using Class A, methodA(), and AspectMock\Test::double(), then inspect how the protected property lookup is handled. Compare the observed null result with the test's expected BAR value; done means the behavior is explained or corrected and covered by a regression test.

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