src/vs/workbench/contrib/tasks/common/problemMatcher.ts/is
		export function is(value: any): value is NamedMultiLineCheckedProblemPattern {
			let candidate = value as NamedMultiLineCheckedProblemPattern;
			return candidate && Types.isString(candidate.name) && Types.isArray(candidate.patterns) && MultiLineCheckedProblemPattern.is(candidate.patterns);
		}