src/vs/workbench/contrib/tasks/common/problemCollectors.ts/WatchingProblemCollector/tryFinish
class WatchingProblemCollector:	private tryFinish(line: string): boolean {
		let result = false;
		for (const background of this.backgroundPatterns) {
			let matches = background.end.regexp.exec(line);
			if (matches) {
				if (this._activeBackgroundMatchers.has(background.key)) {
					this._activeBackgroundMatchers.delete(background.key);
					this.resetCurrentResource();
					this._onDidStateChange.fire(ProblemCollectorEvent.create(ProblemCollectorEventKind.BackgroundProcessingEnds));
					result = true;
					this.lines.push(line);
					let owner = background.matcher.owner;
					this.cleanMarkers(owner);
					this.cleanMarkerCaches();
				}
			}
		}
		return result;
	}