src/vs/workbench/services/themes/common/themeConfiguration.ts/ThemeConfiguration/setFileIconTheme
class ThemeConfiguration:	public async setFileIconTheme(theme: IWorkbenchFileIconTheme, settingsTarget: ThemeSettingTarget): Promise<IWorkbenchFileIconTheme> {
		await this.writeConfiguration(ThemeSettings.FILE_ICON_THEME, theme.settingsId, settingsTarget);
		return theme;
	}