extensions/emmet/src/updateImageSize.ts/getPropertyInsiderStyleTag
function updateImageSizeStyleTag(editor: TextEditor, position: Position): Promise<TextEdit[]> {
	const getPropertyInsiderStyleTag = (editor: TextEditor): Property | null => {
		const document = editor.document;
		const rootNode = getRootNode(document, true);
		const offset = document.offsetAt(position);
		const currentNode = <HtmlNode>getFlatNode(rootNode, offset, true);
		if (currentNode && currentNode.name === 'style'
			&& currentNode.open && currentNode.close
			&& currentNode.open.end < offset
			&& currentNode.close.start > offset) {
			const buffer = ' '.repeat(currentNode.open.end) +
				document.getText().substring(currentNode.open.end, currentNode.close.start);
			const innerRootNode = parseStylesheet(buffer);
			const innerNode = getFlatNode(innerRootNode, offset, true);
			return (innerNode && innerNode.type === 'property') ? <Property>innerNode : null;
		}
		return null;
	};

	return updateImageSizeCSS(editor, position, getPropertyInsiderStyleTag);
}