src/vs/workbench/api/common/extHostWorkspace.ts/ExtHostWorkspaceImpl/getWorkspaceFolder
class ExtHostWorkspaceImpl:	getWorkspaceFolder(uri: URI, resolveParent?: boolean): vscode.WorkspaceFolder | undefined {
		if (resolveParent && this._structure.get(uri)) {
			// `uri` is a workspace folder so we check for its parent
			uri = dirname(uri);
		}
		return this._structure.findSubstr(uri);
	}