src/vs/workbench/services/preferences/browser/preferencesService.ts/PreferencesService/openFolderSettings
class PreferencesService:	async openFolderSettings(folder: URI, jsonEditor?: boolean, options?: ISettingsEditorOptions, group?: IEditorGroup): Promise<IEditorPane | undefined> {
		jsonEditor = typeof jsonEditor === 'undefined' ?
			this.configurationService.getValue('workbench.settings.editor') === 'json' :
			jsonEditor;
		const folderSettingsUri = await this.getEditableSettingsURI(ConfigurationTarget.WORKSPACE_FOLDER, folder);
		if (jsonEditor) {
			if (folderSettingsUri) {
				return this.openOrSwitchSettings(ConfigurationTarget.WORKSPACE_FOLDER, folderSettingsUri, options, group);
			}
			return Promise.reject(`Invalid folder URI - ${folder.toString()}`);
		}
		return this.openOrSwitchSettings2(ConfigurationTarget.WORKSPACE_FOLDER, folder, options, group);
	}