extensions/microsoft-authentication/src/AADHelper.ts/AzureActiveDirectoryService/getCallbackEnvironment
class AzureActiveDirectoryService:	private static getCallbackEnvironment(callbackUri: vscode.Uri): string {
		if (callbackUri.scheme !== 'https' && callbackUri.scheme !== 'http') {
			return callbackUri.scheme;
		}

		switch (callbackUri.authority) {
			case 'online.visualstudio.com':
				return 'vso';
			case 'online-ppe.core.vsengsaas.visualstudio.com':
				return 'vsoppe';
			case 'online.dev.core.vsengsaas.visualstudio.com':
				return 'vsodev';
			default:
				return callbackUri.authority;
		}
	}