src/vs/workbench/contrib/tasks/common/problemCollectors.ts/AbstractProblemCollector/getDeliveredMarkersPerOwner
class AbstractProblemCollector:	private getDeliveredMarkersPerOwner(owner: string): Map<string, number> {
		let result = this.deliveredMarkers.get(owner);
		if (!result) {
			result = new Map<string, number>();
			this.deliveredMarkers.set(owner, result);
		}
		return result;
	}