src/vs/workbench/contrib/preferences/browser/settingsTree.ts/SettingsTreeFilter/settingContainedInGroup
class SettingsTreeFilter:	private settingContainedInGroup(setting: ISetting, group: SettingsTreeGroupElement): boolean {
		return group.children.some(child => {
			if (child instanceof SettingsTreeGroupElement) {
				return this.settingContainedInGroup(setting, child);
			} else if (child instanceof SettingsTreeSettingElement) {
				return child.setting.key === setting.key;
			} else {
				return false;
			}
		});
	}