src/vs/workbench/api/common/extHostWorkspace.ts/ExtHostWorkspaceImpl/constructor
class ExtHostWorkspaceImpl:	constructor(id: string, private _name: string, folders: vscode.WorkspaceFolder[], transient: boolean, configuration: URI | null, private _isUntitled: boolean, ignorePathCasing: (key: URI) => boolean) {
		super(id, folders.map(f => new WorkspaceFolder(f)), transient, configuration, ignorePathCasing);
		this._structure = TernarySearchTree.forUris<vscode.WorkspaceFolder>(ignorePathCasing);

		// setup the workspace folder data structure
		folders.forEach(folder => {
			this._workspaceFolders.push(folder);
			this._structure.set(folder.uri, folder);
		});
	}