Use DOMNodeList with array syntax

This is not only more readable, but even faster [1] (though I doubt this
code is a bottleneck anywhere either way).

[1]: https://3v4l.org/NGEKe

Author: lucaswerkmeister

src/Component.php

@@ -99,13 +99,13 @@ private function getRootNode( DOMDocument $document ) {
 			throw new Exception( 'Empty document' );
 		}
 
-		$rootNodes = $document->documentElement->childNodes->item( 0 )->childNodes;
+		$rootNodes = $document->documentElement->childNodes[0]->childNodes;
 
 		if ( $rootNodes->length > 1 ) {
 			throw new Exception( 'Template should have only one root node' );
 		}
 
-		return $rootNodes->item( 0 );
+		return $rootNodes[0];
 	}
 
 	/**
@@ -250,7 +250,7 @@ private function handleFor( DOMNode $node, array $data ) {
 
 	private function appendHTML( DOMNode $parent, $source ) {
 		$tmpDoc = $this->parseHtml( $source );
-		foreach ( $tmpDoc->getElementsByTagName( 'body' )->item( 0 )->childNodes as $node ) {
+		foreach ( $tmpDoc->getElementsByTagName( 'body' )[0]->childNodes as $node ) {
 			$node = $parent->ownerDocument->importNode( $node, true );
 			$parent->appendChild( $node );
 		}