src/vs/workbench/api/node/extHostTask.ts/ExtHostTask/getVariableResolver
class ExtHostTask:	private async getVariableResolver(workspaceFolders: vscode.WorkspaceFolder[]): Promise<ExtHostVariableResolverService> {
		if (this._variableResolver === undefined) {
			const configProvider = await this._configurationService.getConfigProvider();
			this._variableResolver = new ExtHostVariableResolverService(workspaceFolders, this._editorService, configProvider, this.editorTabs, this.workspaceService);
		}
		return this._variableResolver;
	}