<?php

class A {
    public static $object;
    public function createb()
    { return new B(self::$object); }
}
class B {
    public $object;
    public function __construct($object)
    { $this->object = $object; }
}

$a = new A;
$a::$object = (object) ['val' => 1];
$b1 = $a->createb();
$a::$object = (object) ['val' => 2];
$b2 = $a->createb();

print_r($b1);
print_r($b2);

/* Output:
B Object
(
    [object] => stdClass Object
        (
            [val] => 1
        )

)
B Object
(
    [object] => stdClass Object
        (
            [val] => 2
        )

)
*/