Invade.php

<?php

/**
 * Access/modify any instance private property.
 */
class Invade
{
    public function __construct(
        protected $instance,
        protected $setter,
        protected $getter
    ) {
    }

    public function __get($property)
    {
        return $this->getter->call($this->instance, $property);
    }

    public function __set($property, $value)
    {
        $this->setter->call($this->instance, $property, $value);
    }
}

/**
 * EXAMPLE:
 *
 * class Foo {
 *    private $property = 'bar';
 * }
 *
 * $foo = new Foo();
 * $invade = new Invade($foo);
 *
 * echo $invade->property; // bar
 * $invade->property = 'foo bar';
 * echo $invade->property; // foo bar
 *
 * Source: jszobody/Undies.php
 */