Bug report

DOMNode::appendChild() returns the appended child which means that if I pass a DOMElement to that method, I can be certain that a DOMElement is returned by it. However, PHPStan does not recognize that and assumes that an instance of any DOMNode subclass can be returned.

Code snippet that reproduces the problem

function appendElement(DOMElement $element, DOMElement $to): DOMElement
{
	return $to->appendChild($element);
}

https://phpstan.org/r/4fb72139-58a8-434c-bee8-6cc651dfac65

Expected output

No error.

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