src/vs/workbench/contrib/tasks/common/tasks.ts/ConfiguringTask/getRecentlyUsedKey
class ConfiguringTask:	public override getRecentlyUsedKey(): string | undefined {
		interface CustomKey {
			type: string;
			folder: string;
			id: string;
		}
		let workspaceFolder = this.getFolderId();
		if (!workspaceFolder) {
			return undefined;
		}
		let id: string = this.configurationProperties.identifier!;
		if (this._source.kind !== TaskSourceKind.Workspace) {
			id += this._source.kind;
		}
		let key: CustomKey = { type: CUSTOMIZED_TASK_TYPE, folder: workspaceFolder, id };
		return JSON.stringify(key);
	}