src/vs/workbench/contrib/notebook/browser/view/renderers/webviewThemeMapping.ts/transformWebviewThemeVars
export const transformWebviewThemeVars = (s: Readonly<WebviewStyles>): WebviewStyles => {
	const result = { ...s, ...constants };
	for (const [target, src] of mapping) {
		result[target] = s[src];
	}

	return result;
};