src/vs/workbench/electron-sandbox/desktop.main.ts/DesktopMain/resolveWorkspaceIdentifier
class DesktopMain:	private resolveWorkspaceIdentifier(environmentService: INativeWorkbenchEnvironmentService): IAnyWorkspaceIdentifier {

		// Return early for when a folder or multi-root is opened
		if (this.configuration.workspace) {
			return this.configuration.workspace;
		}

		// Otherwise, workspace is empty, so we derive an identifier
		const emptyWorkspaceIdentifier = toWorkspaceIdentifier(this.configuration.backupPath, environmentService.isExtensionDevelopment);
		if (!emptyWorkspaceIdentifier) {
			throw new Error('Unable to resolve an empty workspace identifier from the environment');
		}

		return emptyWorkspaceIdentifier;
	}