private function addNode(DOMDocument $document, $element, string $key, $value): void
    {
        $key = \str_replace(' ', '_', $key);

        $child = $document->createElement($key);

        $element->appendChild($child);

        $this->convertElement($document, $child, $value);
    }
private function addNode(DOMDocument $document, $element, string $key, $value): void
    {
        $key = \str_replace(' ', '_', $key);

        $child = $document->createElement($key);

        $element->appendChild($child);

        $this->convertElement($document, $child, $value);
    }
private function addNode ( DOMDocument $ document , $ element , string $ key , $ value ) : void { $ key = \ str_replace ( ' ' , '_' , $ key ) ; $ child = $ document -> createElement ( $ key ) ; $ element -> appendChild ( $ child ) ; $ this -> convertElement ( $ document , $ child , $ value ) ; }
Add node.

@param \DOMDocument         $document
@param \DOMElement|\DOMNode $element
@param string               $key
@param string|string[]      $value

@throws \DOMException

@return void
Add node .