src/vs/platform/terminal/node/ptyService.ts/XtermSerializer/_getUnicode11Constructor
class XtermSerializer:	async _getUnicode11Constructor(): Promise<typeof Unicode11Addon> {
		if (!Unicode11Addon) {
			Unicode11Addon = (await import('xterm-addon-unicode11')).Unicode11Addon;
		}
		return Unicode11Addon;
	}